Socket Wiring Advice - Part Dux!

[ebee]

When I used to use traditional bonding then a thin coat of skimming plaster (some use sand and cement instead of bonding first) I was advised that bonding plaster was better than browning plaster and yes I did find it much better but once I tried one coat a few times I found it best for most jobs and the additional expense was more than saved in time saved.

Later on when B and Q changed their one coat I tried the building merchant`s different brands with varying results and none of them seemed as good as the first B&Q one and had various different colours.

Another good thing about the very white one that I found that quite a few of my customers had "not got round to redecorating yet and the bare chase (sometimes next to white anaglypta) did not stand out much, especially if it had a quick lick of paint on it, after 10 years or more! LOL.

Ideally, if doing a chase I would remove surrounding wallpaper first but some of these houses the plaster would not stand it and massive lumps could be pulled off the wall unintentionally, that was pretty common as those houses were about one hundred years old and no damp courses etc. Some were so bad that you were worried that even just looking at them could cause the plaster to fall off (many had a mix of horse hair in them, in quite large clumps too!

So, on a few, I would chase down the wall carefully, not strip paper back (too risky) and plaster in one coat, told the customer to leave it a few days until set. I told them they would notice it dried out in a few days, then if they left it a few days later it would "dry out again" - such was the appearance of it! At that point it was rock hard and could be sanded if required or painted to blend in if required but above all that portion of wall was more secure than the rest of the room so it could be stripped of paper to decorate with minimal risk, the chase was forming a strong bridge holding the plaster to the wall and as you get a few feet away from the chase the existing plaster has to be treated with great care when stripping etc.

Obviously, in such circumstances I reminded them that the finished surface was in fact aligned to the level of surrounding paper and the level of the wall when stripped so a litlle light sanding was required prior decorating otherwise a huge seam would be apparent.

One such job I remember (old lady was an ex-tax inspector) and I called in about six months later because she wanted a small job doing, she had had decorating done, the chases all stood out under her new wallpaper, it was terrible.

She mentioned to me the chases showing and I asked her if she had remembered to ask the decorator to sand down the chases after stripping and before decorating, she had and he had told her that it was not his job to sand them.
Then she told me who the decorator was, I knew him, likeable enough fellow but his proud boast many times to anyone who met him was "I am the cheapest decorator in XXX (Town)" and he most probably was he charged peanuts and was ruf as a badger`s , oh yes.

So, despite the lady asking him to sand down after stripping the walls, he did not, additionally he did not do any lining paper before wallpaper, the wallpaper he used was the cheapest, nastiest you could ever find anyway. All undulations lumps and bumps of the wall along with my chases shone thru at the merest of glances.
Oh deary me!

 

[opps]

Actually not much price difference - it seems that 10 kg of Toupret costs about £33, whereas 10 kg of Easifil costs £30. )n contrast , 12.5 kg of the 'one coat plaster' that ebee and I would usually use only need cost about £16.

The cheapest I can find TX110 10kg for is £42 inc del. The cheapest I can find 10kg of Easifill is £24 inc del. I had thought that the margin was greater, neverthess the fact that is so easy to sand reduces labour times.

I have tried one coat plasters in the past but they were a pig to feather out, so I stick with the filler instead. TBH, my float skills are too limited.

Would not the original plasterboard, plaster and emulion not probably have behaved similarly in response to a 'leak'?

Small short term leaks tend not to damage plasterboard, the skim or emulsion. I did have a customer that had a mains pressure valve snap. I guess that there was about 30 mins of waterflow. I got there about an 90 mins later. I had to get someone to hold a broom against the ceiling whilst I snapped bits of the plasterboard off (before the whole thing collapsed)

 

[JohnW2]

The cheapest I can find TX110 10kg for is £42 inc del. The cheapest I can find 10kg of Easifill is £24 inc del. I had thought that the margin was greater, neverthess the fact that is so easy to sand reduces labour times.

I only glanced quickly at the prices, so may have got it wrong, but there clearly is not a massive price deference. Delivery charges are not very relevant because most tradesmen, and many DIYers, do not pay them - they ther collect materials from suppliers or,, more commonly put together orders sufficiently large that delivery (for the whole order) is either free or trivial. Toolstation are particularly good. One on;y has to send £25 to be able to order up to 9pm for 2free next-day delivery"!

However, price was not my point. I was commenting on the fact that (per their data sheets) the two products you were comparing were pretty similar. In fact, my intuition would probably have suggested to me that the Toupret might be little more 'iffy' - since the "cellulose binder" it contains (I assume essentially "Interior Polyfilla) probably is something which, as least if used alone, could be scraped off, or even wiped off, if it subsequent became wet.

I have tried one coat plasters in the past but they were a pig to feather out, so I stick with the filler instead. TBH, my float skills are too limited.

I'm certainly no expert with a plaster's trowel, but can do pretty well with small areas - and, as has been said, if necessary "one coat" can be sanded pretty easily.

 

[opps]

However, price was not my point. I was commenting on the fact that (per their data sheets) the two products you were comparing were pretty similar. In fact, my intuition would probably have suggested to me that the Toupret might be little more 'iffy' - since the "cellulose binder" it contains (I assume essentially "Interior Polyfilla) probably is something which, as least if used alone, could be scraped off, or even wiped off, if it subsequent became wet.

Not sure which data sheets you are looking at. TX110 contains portland cement. Easifill does not.

As I stated previously, if I pour water into a container that has wet TX110 in it. The filler will go hard. If I do the same with one with that has Easifill in it, it will turn to mush and I can wipe away all traces of it.

I really don't understand why you don't believe me. I have nothing to gain financially from highlighting the weaknesses of Easifill.

I decorate for a living. I have used both products. I could, in the short term, make more money if I stuck to using Easifill exclusively. I don't do so because I take pride in my work. I don't want to charge a grand to paint a room and know that if the customer digs their finger into the filler, it will leave an indent.

 

[JohnW2]

Not sure which data sheets you are looking at. TX110 contains portland cement. Easifill does not.

Since you "highly recommended' Toupret Interior Filler (and TX110 if one wanted something that will set faster on deeper fills)., so it was the Data Sheet for the Interior filler I was looking at, and that does not appear to contain any cement:

As I stated previously, if I pour water into a container that has wet TX110 in it. The filler will go hard. If I do the same with one with that has Easifill in it, it will turn to mush and I can wipe away all traces of it.

I'm rather surprised by that but I would not be surprised by some degree of difference of the sort you mention when comparing TX110 with Easifill, since the former, but not the latter, contains cement. Is it perhaps the case that although you "highly recommend" the Toupret Interior Filler, it' actually TX110 that you use yourself?
Mind you, I';m far from convicted that how a product behaves if one submerges it in water before it has said has any particular relevance to how it will behave/perform when it has set!

I really don't understand why you don't believe me. I have nothing to gain financially from highlighting the weaknesses of Easifill.

I really don't understand either. It's not that I don't believe you, but, rather that what you are saying surprises me and differs from my personal experience. Over the decades, I've had a lot of experience of 'bodging', and have filled holes in walls, chases, holes around electrical back boxes etc. with any plaster-based product I happened to have to hand - and have never experience the sort of problems you have been describing.

I decorate for a living. I have used both products. I could, in the short term, make more money if I stuck to using Easifill exclusively. I don't do so because I take pride in my work. I don't want to charge a grand to paint a room and know that if the customer digs their finger into the filler, it will leave an indent.

Yes, I can understand all that but, as above, having probably used every plaster-based product under trhe sun in my time for such purposes, I don't think I've ever come across any plaster-based product that one could'indent with a finger' once it had set!

I would also suggest that there is probably another theoretical consideration. When filling a hole (e..g. a chase) in a wall, it is theoretically desirable that the filling material is close in physical properties to those of the material used for the rest of the wall - particularly in relation to its behaviour in response to varying humidity and temperature. For that reason, if one fills, say, a chase in a plaster wall with filler containing cement, I think it quite possible that cracks would eventually appear at the interface between 'old and new', due to differential 'movement' of the two materials in responses to changes in humidity and temp.

 

[opps]

Since you "highly recommended' Toupret Interior Filler (and TX110 if one wanted something that will set faster on deeper fills)., so it was the Data Sheet for the Interior filler I was looking at, and that does not appear to contain any cement:

I provided you a link to the MSDS, which says that it is 3% cement.

Here is the link again...

https://www.flints.co.uk/pdf/datasheets/PAT8322%20Toupret%20TX110%20F.pdf

Mind you, I';m far from convicted that how a product behaves if one submerges it in water before it has said has any particular relevance to how it will behave/perform when it has set!

Point taken. Nevertheless if I allow Tx110 to go hard in a container. I cannot wipe it away later, even if I leave water sitting in the tub for days. A tub of cured Easifill will become soft and will wipe away.

Is it perhaps the case that although you "highly recommend" the Toupret Interior Filler, it' actually TX110 that you use yourself?

I do not understand what point you are trying to make. In post 27 I clearly recommended TX110 as a faster curing variant of the Toupret interior filler. Both contain cement- neither will wipe away when cured.

As a professional decorator, I have "highly recommended" a product that I know will not become a mare in the event of a minor leak. Why won't you accept that? I have nothing to gain from lying about Easifill being pants.

Yes, I can understand all that but, as above, having probably used every plaster-based product under trhe sun in my time for such purposes, I don't think I've ever come across any plaster-based product that one could'indent with a finger' once it had set!

This is becoming silly. Easifill remains so soft that you could wipe it away with a wet sponge once it has cured. You cannot do that with the aforementioned Toupret fillers. Easifill is NOT a plaster based product. I cannot comment on plaster based products that you have

I do not understand why you are continuing to argue about this.

If you want, I will send you some TX110 and some Easifill. Fill a hole and then let me know how you get on when you try to sand then.

Look through my posting history. I do not make absurd claims. I am simply trying to warn fellow users that a frequently used product is often in-appropriate. For whatever reason. you seem to have taken umbrage with my advice. Frankly, I don't care, there are too many people on this forum whom seem to think that they know everything about everything . I hadn't thought that you are one of those, but I guess that I was wrong

 

[JohnW2]

I provided you a link to the MSDS, which says that it is 3% cement. ... Here is the link again... ... ,link.

Yes - but that's the MSDS for TX110, not the one for Toupret Interior Filler, which (as below) is the product I thought you were recommending, and which appears to contain no cement..

Point taken. Nevertheless if I allow Tx110 to go hard in a container. I cannot wipe it away later, even if I leave water sitting in the tub for days. A tub of cured Easifill will become soft and will wipe away.

Again, you surprise me, since I would not expect that to be the case with any plaster-based product. I very rarely use Easifill but maybe be doing so fairly soon (using it for its primary intended purpose) and, if so, will do the experiment so that I can see with my own eyes what you are describing!

I do not understand what point you are trying to make. In post 27 I clearly recommended TX110 as a faster curing variant of the Toupret interior filler. ....

I must have misunderstood you. When you wrote ...

I highly recommend the Toupret interior filler, Toupret TX110 if you want something that will set faster on deeper fills.

... I took that to mean that you were primarily "highly recommending" the Interior Filler, OR TX110 IF one wanted faster setting in deeper fills " - which is why I have been looking primarily at the former.

.... Both contain cement- neither will wipe away when cured.

That's were I get confused. As I have said a number of times, I have found no evidence that The Interior Filler contains any cement. The MSDS for it says ..

What am I missing?

As a professional decorator, I have "highly recommended" a product that I know will not become a mare in the event of a minor leak. Why won't you accept that? I have nothing to gain from lying about Easifill being pants. ... This is becoming silly. Easifill remains so soft that you could wipe it away with a wet sponge once it has cured. You cannot do that with the aforementioned Toupret fillers. Easifill is NOT a plaster based product.

I'm not sure where you got that idea from. As you can see from this extract from the SDS, all Easifill products are 50-75% calcium suphate hemihydrate (aka "gypsum", aka "plaster'), the remainder being limestone.

I do not understand why you are continuing to argue about this. ... If you want, I will send you some TX110 and some Easifill. Fill a hole and then let me know how you get on when you try to sand then. .... Look through my posting history. I do not make absurd claims. I am simply trying to warn fellow users that a frequently used product is often in-appropriate. For whatever reason. you seem to have taken umbrage with my advice. Frankly, I don't care, there are too many people on this forum whom seem to think that they know everything about everything . I hadn't thought that you are one of those, but I guess that I was wrong

I think yopu are probably being unnecessarily defensive since I am not trying to 'get at you' or to 'take umbrage' with the advice and recommendations you have given, which I fully accept are sincere, well-intentioned. As I've said, my difficulty has been that you, as a professional in the field, appear to be saying things which differ markedly from my experiences of many years/decades dabbling in the same field as an amateur. Particularly given that I definitely do not regard myself as 'knowing everything about everything" I have therefore been trying to come to understand the reasons for these differences!

The one issue on which we might differ is that (for reasons I explained at the end of my last post) I would probably be inclined to advise people against using fillers which contained cement for repairing interior plastered walls/ceilings, since I would see that as a potential recipe for eventual cracks!

 

[SUNRAY]

I'm really not trying to jump into this discussion and I apologise to Nero for the way this has deviated from the OP.

Having been involded with DIY work for >60 years, particularly electrical and making good I have never knowingly come across any plaster/filler that is soluble once cured however it has raised an interest in my head.

I briefly had a look at the specs for Gyproc Easi-fill and Toupret interior filler earlier (as I believed that was the recommendation) and the only apparent difference seemed to be:-

Not a lot... From my schooldays I hopefully recall Gypsum is Calcium sulphate dihydrate and some other components to provide some strengthening (plaster of Paris being almost pure Calcium sulphate dihydrate which is a fast curingplaster but relatively soft). As a youngster I used lots of POP and that did not disolve in our aquariums. Again from my schoolboy chemistry (which I'll admit I dropped out of prior to my O levelsas it really didn't interest me, so don't claim to be an authority) the difference between hemi, mon, di hydrate is they contain half, one, two atoms of water and the. Primarily the difference between the 2 fillers is the amount of water and the selection of hard components but no sign of cement which I believe is something like calcium alumina.

However afteruse:

seems the Toupret is a soft product when cured. I've never knowingly used this but agree completely with

... having probably used every plaster-based product under the sun in my time for such purposes,

Including copious amounts of Easi-Fill

I don't think I've ever come across any plaster-based product that one could'indent with a finger' once it had set!...

Nor have I ever come across one which I could wash away once cured.

Continuing with the spec sheets
Easi-Fill:

that I believe just about describes all plaster ploducts to some extent, there is no comparable section in Toupret.

When I purchased my first house I went to a local cross between a DIY shop and Iron mongers for something, just as I had been doing for many years. They were sadly having a closing down sale and there were copious quantities (far to heavy to carry to the van in one go) of polyfiller for a silly cheap price, I got the last few internal and a large quantity of external grade (the primary difference between the products being plaster or cement based). In use they behaved almost the same and I could damp trowel with ease without the need to sand. I was very pleased with the results and eventually decorated the chased walls etc. Most of the house had to be redecorated just 5 years later (for domestic reasons) and I won't get into any offers of betting but 30 years later I've been reminded of which 'making good' cracked and showed through the decoration and had to be done again.
My conclusion:

I would also suggest that there is probably another theoretical consideration. When filling a hole (e..g. a chase) in a wall, it is theoretically desirable that the filling material is close in physical properties to those of the material used for the rest of the wall - particularly in relation to its behaviour in response to varying humidity and temperature. For that reason, if one fills, say, a chase in a plaster wall with filler containing cement, I think it quite possible that cracks would eventually appear at the interface between 'old and new', due to differential 'movement' of the two materials in responses to changes in humidity and temp.

Which has also reminded me I made good a chase in the current home with a universal indoor/outdoor filler for a wall light and despite multiple coats of emulsion and the lightweight wallpaper the chase always showed until redecoration and much of it came out while steaming the wallpaper off.

An issue with using a cement based filler in a plaster based finish is the difficulty of doing any rubbing down and making it even when there is a difference between the hardness of the different materials.

An example being these filled holes by a proffesional decorator who also extolled the virtues of cement based products and rubbing down:

Looking 'head on' or feeling them one wouldnt know they are there but walking down the stairs the hall light provides the effect shown.



Now for clarification the TX110 spec sheet shows:

Indicating the internal filler and TX110 have a different base material.

This has taken some 8 hours to write, interspersed with some 100 miles of granddads taxi service, dinner and watching some dancing and drama rehearsal So I apologise for the overlapping information.

Like John I'm not argueing, more like trying to sortout my confusion.

 

[opps]

Since you "highly recommended' Toupret Interior Filler (and TX110 if one wanted something that will set faster on deeper fills)., so it was the Data Sheet for the Interior filler I was looking at, and that does not appear to contain any cement:
View attachment 357433


I'm rather surprised by that but I would not be surprised by some degree of difference of the sort you mention when comparing TX110 with Easifill, since the former, but not the latter, contains cement. Is it perhaps the case that although you "highly recommend" the Toupret Interior Filler, it' actually TX110 that you use yourself?
Mind you, I';m far from convicted that how a product behaves if one submerges it in water before it has said has any particular relevance to how it will behave/perform when it has set!

I really don't understand either. It's not that I don't believe you, but, rather that what you are saying surprises me and differs from my personal experience. Over the decades, I've had a lot of experience of 'bodging', and have filled holes in walls, chases, holes around electrical back boxes etc. with any plaster-based product I happened to have to hand - and have never experience the sort of problems you have been describing.

Yes, I can understand all that but, as above, having probably used every plaster-based product under trhe sun in my time for such purposes, I don't think I've ever come across any plaster-based product that one could'indent with a finger' once it had set!

I would also suggest that there is probably another theoretical consideration. When filling a hole (e..g. a chase) in a wall, it is theoretically desirable that the filling material is close in physical properties to those of the material used for the rest of the wall - particularly in relation to its behaviour in response to varying humidity and temperature. For that reason, if one fills, say, a chase in a plaster wall with filler containing cement, I think it quite possible that cracks would eventually appear at the interface between 'old and new', due to differential 'movement' of the two materials in responses to changes in humidity and temp.

Apropos, the regular Toupret interior filler, I stand corrected. Composition wise, it does not contain cement. I tend to use TX110 and Fibrex (both of which are cement based). I retract my previous recommendation of the regular Toupret interior filler. Apologies.

I do however stand my earlier claim that Easifill can, when cured, be washed away, and that it is so soft that when sanding walls with a DA sander using 80 grit paper, the paint over the filler will rip. It seems likely that the same may be said of the regular Toupret interior filler. Incidentally, Toupret do make a filler that mirrors the quality of Easifill. I have only ever used it once, and to be honest I only used it because I had to feather out a polished aluminium tile trim that was about 3mm past the edge of a wall return. I opted for the Easifill type product because I knew that I could use a wet sponge to retrospectively wipe away any excess that creeped onto the trim.

 

[SUNRAY]

... I tend to use TX110 and Fibrex (both of which are cement based). ...

Is that the toupret Fiberex external filler or a different product?

I had to fill round some new wastepipes through a precast concrete external wall and was given a part bag for the job by the customer, I struggled to wet trowel it, in fact I struggled to get it in the gaps as it was setting so quickly and unworkable within a couple of minutes, additionally it contained fibres which would stick and drag.
At the time I wondered if it had been open for a while and going off.

 

[JohnW2]

Having been involded with DIY work for >60 years, particularly electrical and making good I have never knowingly come across any plaster/filler that is soluble once cured however it has raised an interest in my head.

I'm glad to hear that I'm not alone The duration of my experience of DIY activates is similar to yours, as, it sounds, also is our experience of the behaviour of plasters/fillers etc.

The only recollections I have of any fillers behaving as as been described relation to interior grade(and maybe, to some extent, 'exterior') cellulose-based products such as Polyfilla.

Like John I'm not argueing, more like trying to sortout my confusion.

Indeed so. As I've said and implied, I was uncomfortable finding myself effectively 'arguing' with a professional about matters which I presume are within the sphere his expertise and experience. However, some of the things that have been said just don'y seem to correspond with what I have personally experienced over many decades, and the major performance difference between two specific products which has been the basis of much of the discussion seems to relate to two products which actually seem to be pretty similar. I therefore keep on coming back to the thought of "what am I missing?" - and have yet to get an answer

Your comments about chemistry made me wonder whether that might be at least of "what I was missing", but I actually think not. As you say gypsum ('plaster') is calcium sulphate dihydrate [ i.e. CaSO4.2H2O ], and that is what the Toupret Interior Filler is said to contain. However, if one heats that under the right conditions, one loses some of the water molecules and ends up wth the "hemihydrate" [ roughly CaSO4.½H2O], wich iis what the Easifill products are said to contain - and which, as you've said, is otherwise known as Plaster of Paris. However, by understanding (not guaranteed to be correct) in that when one mixes the hemihydrate with water, it rapidly turns back into the dihyrdate - so I'm not sure that the fact that the two products contain (as supplied) different hydrates makes much difference to what one has one it has been mixed with water!

However, it seems that it gets more complicated than that, since there are apparently at least two variants (alpha and beta) of the hemi-hydrate - but I am then totally out of my depth and don't have a clues to to whether that has any relevance to what we've been discussing

In another attempt to resolve my confusion, I wonder if it is possibly that (rather ironically) professional decorators sometimes (maybe often?) can't afford to wait for the amount of time ideally required for 'complete curing and drying'of fillers etc., before finishing (including 'rubbing down', if necessary and decoration? - and interval that can vary from 'a few days' up to 'a week or three'!?

 

[SUNRAY]

I'm glad to hear that I'm not alone The duration of my experience of DIY activates is similar to yours, as, it sounds, also is our experience of the behaviour of plasters/fillers etc.

✔

The only recollections I have of any fillers behaving as as been described relation to interior grade(and maybe, to some extent, 'exterior') cellulose-based products such as Polyfilla.

Even after sufficiently cured?

Indeed so. As I've said and implied, I was uncomfortable finding myself effectively 'arguing' with a professional about matters which I presume are within the sphere his expertise and experience. However, some of the things that have been said just don'y seem to correspond with what I have personally experienced over many decades, and the major performance difference between two specific products which has been the basis of much of the discussion seems to relate to two products which actually seem to be pretty similar. I therefore keep on coming back to the thought of "what am I missing?" - and have yet to get an answer

✔

Your comments about chemistry made me wonder whether that might be at least of "what I was missing", but I actually think not. As you say gypsum ('plaster') is calcium sulphate dihydrate [ i.e. CaSO4.2H2O ], and that is what the Toupret Interior Filler is said to contain. However, if one heats that under the right conditions, one loses some of the water molecules and ends up wth the "hemihydrate" [ roughly CaSO4.½H2O], wich iis what the Easifill products are said to contain - and which, as you've said, is otherwise known as Plaster of Paris. However, by understanding (not guaranteed to be correct) in that when one mixes the hemihydrate with water, it rapidly turns back into the dihyrdate - so I'm not sure that the fact that the two products contain (as supplied) different hydrates makes much difference to what one has one it has been mixed with water!

First I have to say my chemistry references have been totally from schooldays so I'm rather glad I've not been contradicted. I vaguely remember the manufacturing of a teaspoon quantity of cement but don't recall the formula. Reading the spec sheets today with chemical names immediately brought back the fillers compounds. After 50+ years I'm astounded on a subject I took little interest in

However, it seems that it gets more complicated than that, since there are apparently at least two variants (alpha and beta) of the hemi-hydrate - but I am then totally out of my depth and don't have a clues to to whether that has any relevance to what we've been discussing

Way over my head too

In another attempt to resolve my confusion, I wonder if it is possibly that (rather ironically) professional decorators sometimes (maybe often?) can't afford to wait for the amount of time ideally required for 'complete curing and drying'of fillers etc., before finishing (including 'rubbing down', if necessary and decoration? - and interval that can vary from 'a few days' up to 'a week or three'!?

This is something I do know about, in my first house I had some large areas replastered, as did a neighbour by the same plasterer using the same materials. His rooms were redecorated within days, mine wern't. He had significant issues with finishes and longevity, I didn't.
I've always guffawed at the Nick Knowles TV programs where the painter follows the plasterer within hours... if they were lucky enough to wait that long.

 

[JohnW2]

✔

These several 'ticks' are quite reassuring

Even after sufficiently cured?

I haven't used interior Polyfilla for a fair time, but I have some recollection that there may be a problem if itr gets' very#wet' even if it was 'fully cured prior to that. However, as agreed, neither of us have seen that with any plaster-based product.

First I have to say my chemistry references have been totally from schooldays so I'm rather glad I've not been contradicted. I vaguely remember the manufacturing of a teaspoon quantity of cement but don't recall the formula. Reading the spec sheets today with chemical names immediately brought back the fillers compounds. After 50+ years I'm astounded on a subject I took little interest in

Although I did both O-Level and A-Level Chemistry (about 60 years ago!), I don't think I ever knew much more about the chemistry of these pl;asters etc. than I know today. "Cement" is particularly confusing, since it's pretty ill-defined and despite what may of us probably think/feel, has little relationship to plaster, with any sort of calcium sulphate being only a very small component of cement.

This is something I do know about, in my first house I had some large areas replastered, as did a neighbour by the same plasterer using the same materials. His rooms were redecorated within days, mine wern't. He had significant issues with finishes and longevity, I didn't.

As I implied, roughly what I suspected but, as I also said, rather ironic that (even if not really 'their faulty')) professional; decorators are often not as able to do a job really as properly ("progression ally"??) as a non-professional!

I've always guffawed at the Nick Knowles TV programs where the painter follows the plasterer within hours... if they were lucky enough to wait that long.

I imagine that we've probably all done it sometimes (filled, sanded, and painted all within the period of an hour or three!) but That doesn't necessarily mean that we can (or should) expect to get 'perfect'.

The "Restaurant Impossible" programme amuses me, since they are often see to be painting walls/whatever in the immediate vicinity of where diners are about to sit when the restaurant re-0opens 15 minutes later

 

[ebee]

The "Restaurant Impossible" programme amuses me, since they are often see to be painting walls/whatever in the immediate vicinity of where diners are about to sit when the restaurant re-0opens 15 minutes later

Blimey, that takes me back to a Holiday in Benidorm a few years back.
Near the beach was a premises being done up for opening soon and on an almost daily basis we saw it being done up.
S W M B O commented that it would be open before we returned to blighty.
Sur enough she was correct.
We were amused to see the place full of diners chatting eating drinking whilst sat at the tables and a fellow on his hands and knees completing grouting of floor tiles just inches from them - an accident waiting to happen mee thought.

Whenever I did a rewire I did try and times things so that plastering was finished for the weekend and left to dry out some before any further works was doing mounting sockets and switches and general work activities on the premises.

Another trick, if the house was occupied, was to try to encourage the owners not to put much heating on in areas were plastered until the following day if at all possible, the longer the better.
The other thing was, with aging existing plaster, thoroughly wet the chase area on all areas before mixing any plaster then a quick spray of water on the chases just prior applying plaster - it is amazing how much old plastered walls suck up any moisture and cause cracks in chases if you omit this procedure, you really do want the new plaster to become firmly attached to chases of existing walls and metal back boxes and to remain so for life.

 

[opps]

Is that the toupret Fiberex external filler or a different product?

I had to fill round some new wastepipes through a precast concrete external wall and was given a part bag for the job by the customer, I struggled to wet trowel it, in fact I struggled to get it in the gaps as it was setting so quickly and unworkable within a couple of minutes, additionally it contained fibres which would stick and drag.
At the time I wondered if it had been open for a while and going off.

Fibrex is suitable as an exterior filler. It is also used as an interior filler. I think you might be correct about it being out of date/ gone off. A few years ago, I needed a small amount of bonding plaster. A mate of mine gave me about 1kg. It went hard within minutes but remained fragile days later. He didn't tell me that he had opened it months earlier and that it had been in his van ever since.