water based paint strippers v DCM strippers

[Matt@]

If you are a restorer, french polisher etc then this subject is an interesting one not least because of the furore around using DCM.

I am posting this lengthy thread to help users of both products and in the hope that some constructive comment comes forth here from those that do use these products.

I'm a restorer and have used DCM for nearly 40 yrs. I'm still alive but that doesnt mean using DCM is safe! I have followed the debate re. using DCM stripper since it all kicked off many years ago and my feeling is that I would rather be safe than sorry so I will not use this chemical unless I absolutely have to. If I do have to use it, I don;t need to do so in quantity as I am a restorer not a finisher. I think I can safely say here that many restorers and finishers will still be using DCM (happy to be proved wrong here) due to its effectiveness and I doubt many will admit it.. Yes there are disclaimers to be signed by pro users but checks are not undertaken on the precautions taken by users therefore this product can still be purchased relatively easily. Even as I type this, there is 99% DCM available on Ebay by more than one seller. DCM is the toxic ingredient of DCM paint strippers - where these sellers are able to buy this chemical and why they can flog it on Ebay I don't know! It seems odd that more attention is paid to paint strippers and not to its main ingredient. Anyway, enough of DCM and on to the water based strippers.

I first tried this product about 5 years ago and gave up with it. Anyone who has used the new water based strippers who is a restorer or a finisher will hate this product due to slow working and slow evaporation and staining of the wood. It does actually strip some finishes ok but it takes 4 times as long as DCM. Well, today I have persevered some more with water based stripper and have paid alot of attention to how best to use it. The manufacturers dont go into any real detail about how to use it so heres some tips from an end user who uses this stuff for a living. Todays item to be stripped - an oak ercol style welsh dresser on sideboard base circa 40 yrs old. Unsure of original finish but would have been sprayed. Heres how it went....

1. decant water based stripper into small container
2. use 2" paintbrush and brush a heavy coat of stripper on surface to be stripped ie the whole front of the sideboard base.
3. leave for 1 hour
4. scrape off softened finish with 2" scraper ie one with a handle and push scraper away from you removing finish as you go
5. brush on 2nd heavy coat of stripper
6. leave for 1 hour
7. scrape off as above
8. brush on 3rd heavy coat of stripper
9. leave for 1 hour
10. remove finish residue with either stainless steel wirewool (used for exhaust pipe wrapping) or stainless steel pan scourer pad things from 99p shop for £1 for 8 wads
11. remove remnants of any wetness using green scouring pads again £1 a big pack from 99p shop.
12. use washing up brush as stiff as possible or brass suede brush to get into crevices.
13 leave for 24 hrs to dry off or dry off using a heat gun
14. wash off any remaining staining and residue using 0 wirewool and meths and dry off with kitchen towel
15 leave to dry after meths app for 30 mins

quantity of materials used for one average size dresser
2 litre of water based stripper
3 £1 packs of 99p shop stainless pads
5 £1 big packs of green scourers from 99p shop
30 pairs disposable gloves
3 packs of washing up brushes from 99p shop

You should now have a nice evenly coloured stripped surface ready for finishing. Further cleaning can be done by using oxalic acid solution if needed. The above is what worked for me today but by god what a faff and quite the worst product I have ever used but I think I'm starting to get on top of it. Next I'll do some mahogany. Oak is the trickiest due to the water and any iron about reacting with tannins which is why use scourers and stainless wire wool.

Some further tips based on what I have noticed.

1. stainless steel wire wool and brushes can be washed out and re used. Soak in washing up bowl of water for 1 hr then hose down and dry on radiator
2.pay alot of attention to how long you leave the stripper on for
3. allow a LONG time for item to dry. The surface post immediate stripping looks dire and dreadful and very offputting!!!. Its only when you start washing it off with meths etc after its dried that you get a nice stripped surface.

on the plus side - as its water based, it stays wet for hours unlike DCM which can dry out in 5 minutes and catch you unawares.

For those in a commercial enviroment that have to strip, water based strippers are awful but safe. Time taken is always the biggest consideration when working with your hands and water based strippers can not be rushed!

I'm guessing we have to get used to using them!

All comments welcome from anyone who has any tips for using this type of product - would be good to share notes.......

 

[CHJ]

I've often wondered about the viability of using plastic media blasting on wood for stripping, we used it extensively on aircraft components where glass blasting was too abrasive or water a problem.

The plastic media was available in differing grades and of course blast guns were adjustable for impact performance.

Afraid I did not go into the technicalities beyond choosing the original equipment spec. and relied on the reps to match product to component needs.

There would obviously be a dust containment and entrapment aspect to consider and the cost of the equipment setup, anyone any experience of such.

 

[Matt@]

I've often wondered about the viability of using plastic media blasting on wood for stripping, we used it extensively on aircraft components where glass blasting was too abrasive or water a problem.

The plastic media was available in differing grades and of course blast guns were adjustable for impact performance.

There would obviously be a dust containment and entrapment aspect to consider and the cost of the equipment setup, anyone any experience of such.

yes this is another method but its quite invasive. I know a firm who has led the way with this type of process (not on furniture) and I have seen what it can do in terms of removing a polished finish on furniture. The trouble with timber is it has soft bits and hard bits and any kind of blasting medium will indent the soft parts thus subtly ruining the surface - a power washer tends to do the same thing if used aggressively.The thing is with stripping processes is that there are various types of finish removal required ie graffiti on hard surfaces. Its when we come to furniture refinishing it becomes a massive problem as the stripping process influences the end result hugely. Blasting rips the guts out of a finish and the top skin of timber which may have bleached in the sun etc whose various colour tones need to be retained for the finished job. Water based strippers by their very nature are quite invasive. My dresser has been left with alot of raised grain whereas solvent based strippers are very easily controlled thus being sympathetic to the end result which is why restorers have always used them.

 

[marcros]

Sorry, but what is dcm?

 

[Matt@]

Sorry, but what is dcm?

dichloromethane........... the dangerous ingredient in old style paint strippers ie Nitromores etc

 

[marcros]

Thanks. I knew that it had changed to a new formula and assumed water based but I never knew what used to be in it.

 

[AndyT]

Matt, thanks for writing up this useful note, but what water based stripper did you use?

I bought some 'eco friendly' paint stripper a while back which was non-corrosive - the directions actually said that there was no need to wear gloves - and it was really effective. (I was using it on gloss paint, not sprayed furniture finish.)

See this similar old thread https://www.ukworkshop.co.uk/forums/removing-finish-from-old-furniture-t28095.html

The link I gave then now leads to the suppliers' website: http://www.cirrus-systems.co.uk/removall-eco-friendly-paint-strippers They say their RemovaAll products have "Selective Adhesion Release Agent" technology and work in a different way to the ordinary stuff. I can't see one exactly the same as what I used but it might be worth asking them what they would recommend for what you are doing?

 

[Matt@]

Hi Andy, I used Biostrip. 5L about £27.00. I have a sample of paramose and thats around £54.00 for 5L! Both products smell the same which suggest they have the same make up, havnt tested paramose yet as I've persevered with Biostrip as its cheaper. I'm kinda thinking that all these what they call eco strippers are basically the same in the same way that all DCM strippers were basically the same ie Nitromores, Mylands perfecta, Fiddes Klendoo etc etc. Every manufacturer says their product is the best, no surprise there! and now they all diss DCM, funny that. I will try get a sample of Cirrus to have a go with....

 

[Leif]

There are various kinds of stripper. These people sell a range:

http://www.stripperspaintremovers.com

I've tried three formulations for various surfaces. They sell one which smells of ripe bananas, I forget the active ingredient, ethyl acetate I think. It worked well on acrylic furniture varnish, albeit slowly. Another worked very well on thick oil based paint on architraves. In each case it worked best left overnight, preferably with cling film over the top, not ideal for trades.