Socket Wiring Advice - Part Dux!

[opps]

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.


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'!?

I have conceded that I was wrong to recommend the interior Toupret filler in cases where there might be a leak further down the line.

With regards to drying times. If you try to sand a filler that has not cured, you will soon find that your sandpaper has clogged. In the event that it does not need to be sanded and you paint over wet filler, the paint would remain wet until the filler dries.

If I have time constraints, I use 2 pack polyester resin filler. The deeper the hole, the faster it cures. I can fill, for example, a 35mm light switch back box and sand it about 30 minutes later.

In the case that I referred to previously, the Easifill was dry enough for me to sand. It was dry enough for me to apply a dilute coat followed by 3 full fat coats of emulsion. All was good until the leak made the paint blister where the Easifill had been used. The emulsion on pre-existing skimmed plasterboard simply yellowed and did not blister.

 

[JohnW2]

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.

Fair enough.

As you will realise that leaves me a little uncomfortable, since it means that I am still inclined to offer comments/suggestions to non-professionals that disagree with what you, as a professional, are saying. However, I do believe on the basis of both theory and many decades of personal experience, that it is less that ideal to fill significant/substantial holes/chases/whatever with a filler which is of a substantially different type (hence usually with substantially different properties/behaviour - and would therefore always be inclined to advise against filling significant holes in plaster with cement-based fillers (although I'm sure I' will have done it in my time )

You will have seen (and to some extent responded to) my discussion with Sunray about the (rather ironic) possibility that falling slightly short of a 'perfect' end-result may sometimes be considered by a professional to be 'a price worth paying' for expediency, whereas a delay in completing a job is not usually a problem for a non-professional. ... but I have no idea as to the extent to which some professionals might be influenced b

 

[ebee]

You will have seen (and to some extent responded to) my discussion with Sunray about the (rather ironic) possibility that falling slightly short of a 'perfect' end-result may sometimes be considered by a professional to be 'a price worth paying' for expediency, whereas a delay in completing a job is not usually a problem for a non-professional. ... but I have no idea as to the extent to which some professionals might be influenced b

I will agree with that statement.
Whilst I have always endeavoured to do a "proper job" at all times I do accept that there is often a time constraint, more time means more expense as well as meaning you can get onto the next task. Providing it does not lead to a "race to the bottom" in prices and standards. I have never joined in such a race and at times it has cost me work. So be it.
I do recognise that, at times, something less than perfect could be appropriate under certain limited conditions, safety must never be compromised but appearance might be sacrificed for a small temporary period.
I do not like spending more than I need to on tools and materials or when paying for goods or services just like anyone else.
If I`m doing a job for myself then time taken/period it is a messy state is usually not as important but a job for a customer is different.
It saddens me to see jobs that a trade has botched for a customer though, there is a limit to what is acceptable.
There is a difference between perfect and acceptable.
I accept that cost can be one consideration.

 

[opps]

Fair enough.

As you will realise that leaves me a little uncomfortable, since it means that I am still inclined to offer comments/suggestions to non-professionals that disagree with what you, as a professional, are saying. However, I do believe on the basis of both theory and many decades of personal experience, that it is less that ideal to fill significant/substantial holes/chases/whatever with a filler which is of a substantially different type (hence usually with substantially different properties/behaviour - and would therefore always be inclined to advise against filling significant holes in plaster with cement-based fillers (although I'm sure I' will have done it in my time )

You will have seen (and to some extent responded to) my discussion with Sunray about the (rather ironic) possibility that falling slightly short of a 'perfect' end-result may sometimes be considered by a professional to be 'a price worth paying' for expediency, whereas a delay in completing a job is not usually a problem for a non-professional. ... but I have no idea as to the extent to which some professionals might be influenced b

Are you really suggesting that if you run a chase in a victorian property that has the old gritty 30/40mm deep lime plaster with a newer scrim coat over it, you will use the original products? If you need to move a socket in a newer property would you replace the brick that had previously been hacked to let the socket in? If you need to fill a hole in wood do you source the same timber and use a plug cutter to create a plug that you hammer/glue in?

Expediency? this thread is becoming silly. I was simply trying to suggest that Easifill, which is a product that is very different to your average plaster has downsides. You seem to be simultaneously defending the use of it and discounting it because it is not the same as the original material that was used.

I try to use fillers that are as close as possible to the hardness to the surrounding area. Too soft, the sander will leave a furrow. Too hard, the sander will dig into the existing plaster. I have sanded loads of chases filled by plasterers. They told the customer that they were good to paint as is. It is pretty much impossible to patch in plaster without leaving a ridge at the trailing edge. On each occasion, I sanded them back and often used a fine coat of filler over the top.

 

[SUNRAY]

I try to use fillers that are as close as possible to the hardness to the surrounding area.

Slightly different to our expectations from your previous advocation of using a cement based filler in interior walls where they tend to be covered with a plaster/gyproc product.

 

[SUNRAY]

Too soft, the sander will leave a furrow. Too hard, the sander will dig into the existing plaster.

Exactly my point when I posted this:

An example being these filled holes by a proffesional decorator who also extolled the virtues of cement based products and rubbing down: View attachment 357497
Looking 'head on' or feeling them one wouldnt know they are there but walking down the stairs the hall light provides the effect shown.