Varnish stripping problems

[davelanthier]

The interior finish of this an old wood canoe appears to have the original clear varnish with a second old yet later clear coat of something unknown . The second coat has become checked and dark brown . The usual chemical paint stripping agents seem to turn these finishes into a thick slime which is not water soluble and completely plugs up the cleaning tools . It leaves a chewing gum type of residue . I have tried several solvents to no avail . Laquer thinner and acetone do work somewhat but not well enough . I'm wondering if the second coat is shellac ? Any ideas or assistance greatly appreciated .

 

[Paul Miller]

Shellac

Hi,

I was just speaking with Mason Smith of upstate NY yesterday about stripping Shellac out of an old canoe. Mason said he has run accross this often and it produces just as you have described. Problem is, I can't remember what he said would work on it. He mentioned TSP but I can't remember is he said it worked or did not work. Maybe he's out there somewhere.

Good luck,

Paul

 

[Larry Bowers]

Hi Dave,
have you tried methal hydrate or denatured alcohol? I have not tried either one but read where it does work on shellac. Hope this helps.

 

[David Niles]

varnish stripping problems- removing shelliac

Denatured alcohol works very well on shellac. It is used to refinish alligatored surfaces on antique furniture by very slightly dampening a cloth with denatured alcohol and lightly rubbing. The very slightly damp cloth partially disolves the shellac and redistributes it, still leaving the all important patinia. Denatured alcohol in any greater concentration than "slightly damp" will remove the schellac finish. What would be a disaster for antiques (removing the patina) is just what you want with this canoe, so use denatured alcohol in full strength. It won't work on the varnish, so you are going to have to use stripper on the varnish after removing the shellac. If you are lucky someone has found something that will remove both finishes in one step and post it, I'm unaware of such a product.

Dave

 

[Andy Hutyera]

I've had great success removing varnish by mixing equal parts of alcohol and lacquer thinner. Sometimes adding a bit of stripper to the solution gives it a little extra kick. The secret is to use a paint brush that has had the bristles cut short so that it scrubs. It will clean out the cracks and other stuborn places. You can keep rinsing the whole thing with a clean solution of the same stuff and literally wash off the old finish. If the outer layer is indeed shellac this brew will cut through it and also work on the varnish underneath. It has the added benefit of being a whole lot cheaper than stripper and no methylene chloride. Of course you need good ventilation and no open flames. Otherwise you may get a great buzz and/or get your whiskers singed.