Dubbing plane iron when flattening

[SammyInnit]

The problem with that is that MDF is really very, very soft so a combination of the lubricant in the paste wetting the MDF and the softness that nice flat surface might last as long as 30 seconds..... To grind steel you need an abrasive and ideally a lubricant of some description (to carry away the swarf and to prevent clogging) so that makes float glass or a flattened steel plate two of the best grinding surfaces

You'd be surprised to find that many professionals recommend MDF and diamond paste over the latter, then.

A Google search will bring up many results. Some being for and some people against on a personal preference basis but the 'last as long as 30 seconds' statement is hyperbolic at best.

https://www.instagram.com/p/_4iMD2Ol4K/

http://www.leevalley.com/us/wood/page.aspx?p=58754&cat=1,43072

 

[Deleted member 174758]

No disrespect, but my bias against MDF as a surface for abrading is based on something like 35 years professional experience of machining and installing the stuff as a practicing joiner and I therefore cannot recommend it for anything where a sharp edge under pressure will be applied. Some imported MDF is decidedly patchy in terms of surface finish and hardness as the result of poor handling and storage between the mill and the end user. The worst stuff I've ever used is nothing more than expensive, thick blotting paper which absorbs finishes such as paint about as quickly, but often patchily, and it can also suffer from grain raising. Good quality MDF from a reputable supplier stored and used in a dry, heated professional workshop is likely to give somewhat better results than a piece of Chinese MDF from the local B&Q which has been stored in a damp, unheated shed at home from 6 months.

Your reference specifically says "stropping" which to me is the final polishing after coarse and fine grinding have been done. If you are attempting to take a low spot out of an iron then that initially involves coarse grinding at low grit numbers (40 to 60) in the same way that you'd use a coarse wheel or belt on a grinder to remove nicks from the edge of a chisel. 6 micron is way finer than that and will make not a jot of difference if you are trying to grind something flat as opposed to just polishing it to a nice shine

 

[Deleted member 174758]

The plane iron is made by ray iles and I think it was about £25 new.

I'm actually quite surprised. Ray's stuff is normally pretty decent. Have you talked to the vendors about this (assuming it's someone like Workshop Heaven)?

 

[Roger928]

Does ray iles actually make any tools?
I see his name comes up here... https://www.oldtoolstore.co.uk/

As proprietor. And you can purchase a second hand Stanley No4 plane for £25 quid.

 

[harlow]

I'm actually quite surprised. Ray's stuff is normally pretty decent. Have you talked to the vendors about this (assuming it's someone like Workshop Heaven)?

The iron is from workshop heaven but I haven't contacted them as I didn't check how flat the iron was before I started using sandpaper. Are you using the ultex diamond stones from ITS and if so what grit do you use. I have been using 120 and 80 grit alox sandpaper but I will try the silicon carbide wet and dry I have.

 

[Deleted member 174758]

The iron is from workshop heaven but I haven't contacted them as I didn't check how flat the iron was before I started using sandpaper.

If you have any problems Matthew (?) at WH is normally an extremely helpful guy

Are you using the ultex diamond stones from ITS and if so what grit do you use.

Yes. I have a 300/600 grit 8in plate and a 1000/1200 grit 8in plate. They come up on sale from time to time (2 to 4 times a year) at a really good price. As lapping plates they are much better than the original plates that ITS sold. They are conveniently marked with the grit in the diamond pattern. Alright, so they aren't DMT stones but they are more than good enough to deal with any and all on-site honing and sharpening I'll ever undertake

I have been using 120 and 80 grit alox sandpaper but I will try the silicon carbide wet and dry I have.

To grind nicks out of my chisels and plane irons (a common bugbear in site carpentry) I resort to taking the tools home and using a dry grinder. Dip the tools regularly in a bowl of cold water to prevent overheating! That grinder is currently an old no-name double-ender fitted with an O'Donnell Ruby 46 grit wheel - Google "Toolpost" and "ruby wheel" if interested in a far better quality stone - BTW it shouldn't be used on soft metal or unhardened steel).

When I start to flat a new chisel or iron I tend to start at 300 grit (diamond hone) then go downwards in grit number (i.e. upwards in grit size) until I'm happy that I'm cutting sufficiently quickly, I then have to work back up the grits (something like 60 - 80 - 120 - 180 - 240, etc) before I can switch to the diamond. Only go down to the minimum grit number you can live with in terms of how long it is taking you to do a job. When working up the grits after your heavy grind all successive grits will require a lot less strokes before you can move up to the next grit. All grits are used wet with a lubricant (paraffin, lapping fluid, sewing machine oil, hell, even WD40) to prevent the papers or stones from clogging and when changing grit the iron is always thoroughly wiped off to prevent cross-contamination of higher grit numbers with an over-sized grain or two of grit from the previous grade as this is almost guaranteed to scratch the surface (all pretty standard metalworking stuff, really)

I actually flatten my backs on a piece of marble (a cutting/pastry board from Argos or all places - dead flat when checked) often using 40 or 60 grit paper to start with. The grit is specific - you need to remove material, not polish it, and you shouldn't need many strokes on the coarse paper to do that. Once you've flatted the back once you should never need to do it again.

 

[harlow]

If i start with 40 grit what type should I buy.

 

[Deleted member 174758]

Carborundum or silicon carbide. Get a sheet each of 40, 60 and 80 grits and start with the 80 first to see if it is cutting fast enough (go to the 60, then 40 if it isn't). I actually stick mine down using spray-tack type adhesive which came from the pound shop and use a scraper to take them up when the sheet is no longer cutting

 

[harlow]

Carborundum or silicon carbide. Get a sheet each of 40, 60 and 80 grits and start with the 80 first to see if it is cutting fast enough (go to the 60, then 40 if it isn't). I actually stick mine down using spray-tack type adhesive which came from the pound shop and use a scraper to take them up when the sheet is no longer cutting

Would you have a link to what paper you would use as I cannot buy 40 or 60 grit around me and the stuff they have in poundland looks rubbish. I seen a video on youtube where they tried to flatten a hock blade on a diamond stone but when they found out it had a belly they used the ruler trick instead of wasting time trying to remove the belly.

 

[Deleted member 174758]

Got a Halfords in the area? They sell "wet and dry" paper and "emery cloth" in various grits. IIRC they go right up to about P2500. Not the cheapest, but available and the stuff works