What is this wood coating?

I am heat stripping woodwork in a 30's house, which I think is the first time that it has been done. Anyway, the top several coats are no problem but underneath is a brown coat that turns into a grunge of tar consistency, sticks to the scrapers then hardens like rock. My first thought was that is was varnish, however there is a pink primer beneath so do not think that likely. Any ideas as to what it might be please?

Reply to
Broadback
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I don't know but you need to be aware that pre-war paint was high in lead which is very toxic.

Reply to
DIY

I dunno what it is either but it seems to be very common, my house had it too.

Andy

Reply to
Andy

I think it's what used to known as "scumble". They would slap this stuff on, then go over it with a comb-like tool to give a pattern and texture.

Reply to
Roger Cain

That was a form of varnish. The finish was flash, not textured, the pattern made by dragging a brush over it. I've done a lot of that, as a child.

To remove the dark brown stain and varnish on the floors in our '30s house we used a hired industrial sander. Worked like a charm but caused a heck of a lot of dust, as discussed in a recent thread here.

Mary>

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Reply to
Mary Fisher

The stuff I had on our stairs (so many stairs...) was quite brittle. I managed to chip the surface up by gouging it with a broad chisel (cold) then ripping it off with one of those pull type paint scrapers. Took the residue off with a heat gun.

Reply to
baxter basics

Probably white paint 8-)

Any paint of this period will have been based on natural oils which turn into a thermosetting resin with age (and they'll now be a lot darker than they used to be). If it comes off cleanly, then think yourself lucky. That pink primer often helps in getting a clean finish. I find a bowl of iced water handy to keep the shave hook cold is a big help.

If you scrape it with a blunt warm scraper while it's still too hot and fluid then it will smear over the surface of the wood and entrer the surface a bit. You really can't shift this afterwards without heavy sanding and it looks awful. If you're going back to bare wood, then consider reputable tank stripping (fresh tank and hot, not diluted, luke-warm and tired so that the timber splits first).

You might encounter a bitumen-based black or very dark brown paint, typically on the borders of floors around a large rug. This is Blair's own job to shift and heat really doesn't help. It makes stripped floors twice as much work (and twice as much extra-coarse sandpaper) as without it. A Multimaster with the sideways oscillating scraper can be useful if it's thick, but it's still tiresome.

Reply to
Andy Dingley

The "pink primer" might be red lead, which doesn't respond well to caustic stripping and is obviously not something you'd want to sand. It may have been outlawed by the 30s but was common on Victorian furniture. IME you never really get rid of that brown stuff (whatever it is). It liquifies but then soaks back into the grain and looks dirty

Reply to
Stuart Noble

The only way to get the brown stuff off completely is to burn it off to start, then go over the area several times with thin coats of paint stripper and fine wire wool.

I had to do several complex window frames in this manner, it was a huge amount of work. Anyone considering stripping their painted wooden windows back to bare wood then varnishing beware, you're buying yourself a hell of a job.

Andy.

Reply to
Andy

I too was told it was scumble. In our 1927 house we got it off the flat areas with a blowtorch and skarsten scrapers [I still have the scars from doing the top of the door casings] More delicate areas were done with that Ronstrip stuff that you mixed to a paste, covered with paper or clingfilm and then removed a few hours later.Even the wallpaper in the hallway was covered in it. It was that 'Lyncrusta?' with the sort of cardboardy cover strips over the joins. Nice job

Reply to
Grumpy owd man

Thanks folk, it comes off easily, however, as I said it sticks to the scrapers and transfers back onto the wood if not very careful. I'll try the iced water trick.

Reply to
Broadback

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