Stripping a dark finish from wood

[ppppenguin]

This is actually a piece of furniture, not a radio cabinet, but much of this would be of relevance to subjects embraced in these forums.

It's a cupboard, of no particular age (1930s to 1950s?) or value, made from a mixture of solid oak and what looks like oak faced plywood. Currently finished very dark and I would like it something close to it's natural wood colour which is visible on the inside.

I decided to do some experiments on the inside of a door and it's a stubborn brute and of course there's a lot of it to strip. I've tried dry (hand) sanding, which clogs the paper in seconds, wet sanding which is a little better, wirewool, both wet and dry. Also all of the above with white spirit and with meths. All of these remove the finish after a fashion with about the same amount of difficulty. Definitely not french polish as meths doesn't soften it. Could be a cellulose lacquer. Even after a lot of sanding it's difficult to get all the dark colour out of the grain.

Any suggestions?

I'm thinking of finishing it very simply with wax since it won't get a lot of wear and tear. Any thoughts on this too?

As you can probably guess, I'm not really a woodworker!

[Aerodyne]

Seems to me to be a candidate for paint stripper, Jeffrey. Buy a nice pair of rubber gloves and some medium to fine wire wool to help the stripper and be prepared to use several coats, stripping off the softened goo and then recoating. Do one panel or side at a time, clean off with white spirit to kill the stripper action. Use good quality stripper such as Nitromors and whatever you do, despite the instructions, don't leave it too long or it'll dry and be impossible to shift. Use white spirit, not water, to clean brushes with. Avoid sanding if at all possible or you'll make work for yourself.
-Tony

[Mike Phelan]

I'd say it is cellulose as well, Jeffrey.
I would also second Tony's suggestion of Nitromors and never sanding it.
Try to get the side you are stripping horizontal, as well.

For finishing, either Danish oil - brushed initially, then some 000 steel wool followed with a cloth.
OR:
Clear acrylic lacquer, several coats with 000 wool between coats.
OR:
French polish (if you are a masochist) - not very good if water or alcohol near it! Keep away from the G&Ts!

[ppppenguin]

Tony, Mike, thanks for the advice. I've got heavy weight rubber gloves, 0 and 0000 wirewool and some Scotchbrite pads. Just got to get some Nitromors. Would a well sharpened paint scraper (the traingular shavehook variety) be useful for removing the bulk of the Nitromors laden crud?

I'm not sure about danish oil. I recently did a lot of work on my hall floor which is original 1920 solid oak strip. I plugged the big holes using offcuts and the smaller holes with sawdust and glue. I scrubbed it heavily with a stainless steel scourer, detergent and water. maybe a bit brutal but it worked. An amazing amount of crud came out. Then hand sanding (I don't have a decent electric sander) and it didn't look too bad. Maybe I should have hired a floor sander but I ddn't.

Then I gave it a coat of danish oil and it darkened far more than I wanted. I think I'll give it another (lighter) scrub down, followed by a wipe with white spirit and a few coats of acrylic floor varnish. So I'm a bit unhappy with danish oil at the moment. Still looks far better than it did before but not the lightish oak colour that I'd hoped for.

[chipp1968]

I wouldnt go anywhere neat a triangular shave hook ! horrible horrible . I would advise nitromores repeated for each layer scraping with a new stanley blade with the grain .Hold it with both forfingers and thumbs tilted forward , pressure from thumbs ,and scrape ... then wire wool and nitromors . Expect sore fingers ..then after cleaning off fine sandpaper not the oldfashioned type ,with the grain followed by a very fine sandpaper ,then after thourough dusting a coat of sanding sealer, followed by wax polish put on with fine wire wool with the grain and buffed up with cloth .Or danish oil one or two coats follwed by wax and wire wool etc .I have dry stripped stuff before with just the scraper but its dusty and can leave marks so wet method may be better for you .Always best to seal the wood before waxing , makes a much better finish

[ppppenguin]

chipp, thanks for the scraper hint. I just tried a Stanley blade dry and it gets the bulk of the old finish off very quickly. That should mean a lot less Nitromors. Definitely not comfortable to use. I suspect that what I need is an old fashioned cabinet scraper which seems to be a bit of sheet steel held in a similar way but rather bigger and easier to use as it bends more easily. I tried with a 6" steel rule and that worked nicely but I don't want to abuse a nice steel rule. I'll look in my scrap metal box to see if there's something suitable.

[Aerodyne]

There are plastic handles to take Stanley blades for use as scrapers - hardware shops often stock. Saves fingers. It is always worth scraping dry if the finish is susceptible to that form of attack! Chipp is right - take care with the blade corners, they tend to dig in rather. I prefer to use a plastic scraper and wire wool with Nitromors.
Don't understand your problem with Danish oil, however. I've always achieved a virtually clear finish, though stain can be added to it if a tint is desired.I can only think that you scored the surface with sanding and that caused pick-up of excess oil which soaked in and darkened. Well, maybe!
-Tony

[chipp1968]

Yes cabinet scraper would be good , Ive heard of people using glass but not advisable .The fact that you can slightly bend the scraper seams to help .Sharpness is most important meaning less effort.
I think the darkening floor problem is not the oil but the floor,I find if anything the oil gets yellower /orange the more thats applied, but on bare wood would only darken slightly , bit more than wetting it does . A pleasing affect with dry scraping 1920s dark oak stuff is that the grain will retain some of the dark finish so that with care ,the grain can sometimes be enhanced and more attractive than if totaly stripped ,The plywood stuff is more difficult to strip than the solid though .

[ppppenguin]

You're right about the plywood being harder to strip. The solid framing is harder to get at with a scraper so that's going to be largely wirewool and Nitromors. The plywood is large areas which are easy to get at so I'll use a dry scraper to get off most of the finish and then complete the job with Nitromors.

The ply also ends up a slightly different colour. It's a bit yellow while the oak's a bit pink. Once it's varnished/oiled/waxed it will probably all look fine.

The danish oil I had looked a bit dark in the bottle so maybe it was tinted. Didn't claim to be tinted when I bought it from Screwfix but they no longer stock that particular type so I can't check back with the catalogue.

[Mike Phelan]

I use a cabinet scraper that I made years ago like this:
Piece of mild steel strip, about 1/16" x 4" x 8".
Drawfile one short edge until perfectly smooth and flat, then, using a piece of hardened steel rod (smooth end of drill or rat-tail file) burnish the edge at a slight angle to "turn the edge" over. Like this
Then, just take the corners off slightly so as not to make grooves in the wood (useful tip for plane irons as well)

[ppppenguin]

As a trial I've stripped one of the doors and it's looking much better. Still need to try and get a bit more of the dark stuff out of the grain. The end grain is particularly tough here. Any suggestions?

I found a brass wire brush to be useful for getting stripper laden gunge off the surface, especially round any more intricate parts. Doesn't seem to scratch the wood.

For sealing the wood before waxing I've seen something called Sanding Sealer. Is that what I want? http://www.screwfix.com/search.do;js...sanding+sealer

Should I use it before varnishing if I decide to varnish?

The stripper I got was actually Wickes own label as they didn't have Nitromors, Rustins etc. It's got methylene chloride and methanol in it so it sounds amply nasty enough to do the job and it certainly acts pretty quickly on the cellulose finish. Is Nitromors actually any better?

[Zulu95]

Ready Strip should do it.
http://www.dtep.com/ready-strip.htm

[Dave Moll]

My can of Nitromors varnish remover says it contains dichloromethane and methanol, which sounds pretty similar. My knowledge of chemistry is not sufficient to tell whether they are similar (or even different names for the same chemical).

Incidentally, I also take the attitude that if there isn't a sign saying "harmful", it isn't worth bothering with

[Sam]

Well, my vauge memory of A-level Chemistry says they are both Hydrocarbon chains with chlorine atoms replacing some hydrogens. Wikipedia comes to the rescue though: http://en.wikipedia.org/wiki/Dichloromethane

They are the same!

[ppppenguin]

Originally Posted by Dave Moll

My can of Nitromors varnish remover says it contains dichloromethane and methanol......

I'm being a bit old fashioned. When I did my A level chemistry we learnt a lot of traditional names such as methylene chloride alongside the formal ones such as dichloromethane. The can actually gives the formal name but I still think of it under its traditional name. Anyone for propan-123-triol? That's the formal name for glycerol or glycerine.

Back to stripping. I'm sure my cheapo Wickes stripper is near enough to Nitromors and it certainly does the job. The stuff recommended by Zulu95 sounds very nice but I'd have to search for something similar in the UK. I've heard of caustic soda (sodim hydroxide) based strippers but not seem them around recently.

[Mike Phelan]

ISTR that NaOH was used in the 1980s (?) when there was a fad for stripping furniture - companies were set up that used large tanks of sodium hydroxide.

They all seem to have gone now; maybe one reason was all the stripped furniiture fell to bits as the glue dissolved.

All the strippers I have come across (ooh missus ) seem to smell like Nitromors now. I find it is important to try to keep to one horizontal surface at a time, and not to let it dry out.

[ppppenguin]

It seems like there are all sorts of low toxicity paint strippers such as this one: http://www.decoratingdirect.co.uk/viewprod/e/ECOHS/ and this one: http://www.bcaviation.co.uk/paint_st...t_stripper.htm

Whether they work as well as claimed is another matter. It's difficult to imagine how you can strip paint without using something rather nasty.

Mike, if I were you, I'd stop sniffng paint stripper

[kalee20]

With regard to the chemistry of the stripper, the two chemicals mentioned are Dichloromethane, and Methanol.

Dichloromethane, formerly known as methylene chloride, consists of a carbon atom bonded to two hydrogen atoms and two chlorine atoms. It is a fairly volatile solvent (methane, which is one carbon atom bonded to four hydrogen atoms), is a gas. But dichloromethane is also pretty aggressive as a solvent. As well as paint stripper, it's used for decaffeinating coffee, and it strips skin from hands easily. It can also be absorbed into the body through the skin, and it is bad news for liver and kidneys.

Methanol, formerly known as methyl alcohol, consists of a carbon atom linked to three hydrogen atoms and one oxygen atom. This is further linked to a fourth hydrogen atom. It is the simplest alcohol that exists. The next simplest, ethyl alcohol, is the stuff in booze and we know what the effects of that are on the human body. Methyl alcohol is at least 20 times more toxic, attacking brain cells as well as kidneys, and symptoms of poisoning frequently include death.

So, with all these fluids, heed the warnings! An accident caused by irresponsible use, is likely to fuel demands for banning them! And that would be bad news for the majority of responsible users.

[Zulu95]

I have used Ready Strip and it works as stated. I was able to strip a 40 year old painted bathroom vanity and then stain it. I plan on stripping my living room oak flooring this spring using it before sanding and revarnishing.

[Telleadict]

Just a quickie.

For all kinds of wood finnishing (and stripping) materials by mail order you could try http://www.axminster.co.uk -- good for tools too.

bye for now
William