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Interior Passenger Car Paint Removal
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Author:  skytop45 [ Tue Jan 31, 2012 2:19 pm ]
Post subject:  Interior Passenger Car Paint Removal

I am looking to do some paint removal on the interior of a 1947 Milwaukee Hiawatha car. I am not sure if the paint is oil based or latex, but I am looking for suggestions on how to remove it without damaging the Milwaukee's signature wood veneer below. Any suggestions would be greatly appreciated.

Regards, Justin Nelson
Sacramento, CA

Author:  Randy Hees [ Tue Jan 31, 2012 4:09 pm ]
Post subject:  Re: Interiot Passenger Car Paint Removal

If it is a 1947 car the paint is unlikely to be latex. Is the finish below veneer or could it be faux graining over steel?

If it is a wood veneer, I would suggest testing a variety of the chemical (not "safe") strippers, with protective gear and lots of ventilation, trying to find one that penetrates the paint, and attacks the varnish over the veneer. (varnish is usually more easily attacked by the solvents used in stripper than the paint) If you find the right one you will find the finish "breaks" at the varnish layer and comes off with minimum fuss and scraping. Sometimes the correct stripper isn't a stripper, but instead a solvent like lacquer thinner or alcohol.

I had one finish, over shellac that worked with one of the cheap thin runny strippers, paint it on, give it a very short sit time (one or two minutes), then whipped off with a rag. If you let is sit too long, it became a real mess.

Be aware of fumes, and fire protection.

You may need a different stripper for the second coat, possibly using a tooth brush or a brass bristle brush and tooth picks or bamboo skewers. It is slow tedious miserable work... If done correctly, with a little luck you can restore the original paneling to its original finish... If you rush it you can make a lot more work for yourself.

You should probably test the paint for lead, and collect all your scrapings in a seal-able metal container to be disposed of as hazardous waste. Be aware that rags and some solvents can be sensitive to spontaneous combustion.

Randy

Author:  skytop45 [ Tue Jan 31, 2012 4:21 pm ]
Post subject:  Re: Interiot Passenger Car Paint Removal

should clairify, the paint in questions is not original and was added sometime in the last 30 years.

Author:  colfaxstation [ Tue Jan 31, 2012 5:02 pm ]
Post subject:  Re: Interiot Passenger Car Paint Removal

Or, as an alternative, try a heavy duty heat gun and scraper. We've found that the varnish may go first and all layers strip. Then use the chemicals to clean the residue.

Author:  Dave [ Tue Jan 31, 2012 5:32 pm ]
Post subject:  Re: Interiot Passenger Car Paint Removal

Ditto - heat gun to soften the varnish, and the paint over the varnish scrapes off and hardens into chips you can sweep up for disposal. Then you can use any commonly available appropriate solvent to remove or clean the varnish from the veneer. you will have a lot less hazmat problems keeping the paint in intact dry chips rather than as part of a chemical slurry. And, yes, do ventilate adequately no matter what you do.

dave

Author:  WesternStar [ Tue Jan 31, 2012 6:53 pm ]
Post subject:  Re: Interiot Passenger Car Paint Removal

Try the Silent Paint Stripper: http://www.silentpaintremover.com/spr/index.htm

We'd had great results on oil-based paint, shellac, and even really old spirit varnish. It is a lot cleaner to work with than chemicals. It got our panels down to a just a thin layer of shellac and then we cleaned that up with alcohol.

When used as directed, it will NOT generate temperatures high enough to vaporize lead. Conventional heat guns WILL vaporize lead contained in any lead-based paint.

--Richard

Author:  Dave [ Tue Jan 31, 2012 7:34 pm ]
Post subject:  Re: Interiot Passenger Car Paint Removal

Varnish softens at a lower temperature than the vaporization temperature of lead paint. You could leave it on one place too long if you want to and melt and vaporize parts of the paint. Why you'd want to do that is another question.

dave

Author:  WesternStar [ Tue Jan 31, 2012 9:24 pm ]
Post subject:  Re: Interiot Passenger Car Paint Removal

The air exiting a conventional heat gun may be 800 or more degrees F. While it is heating up the paint and varnish to make it soft, surface temperatures rise quickly to that of the gun exhaust. Lead melts at approximately 600 degrees F.

--Richard

Author:  Dave [ Tue Jan 31, 2012 11:40 pm ]
Post subject:  Re: Interiot Passenger Car Paint Removal

Ok, at what temperature does the varnish soften?

dave

Author:  David Johnston [ Wed Feb 01, 2012 12:45 am ]
Post subject:  Re: Interiot Passenger Car Paint Removal

If there is veneer under the paint and it was put on with hide glue, heat may soften the glue and let the veneer come off. I would suggest you test carefully and go slowly until you get a system that works for your car. If the paint is latex, it might sand off easly.

Author:  WesternStar [ Wed Feb 01, 2012 11:43 am ]
Post subject:  Re: Interiot Passenger Car Paint Removal

Dave makes a valid point: test your particular situation before applying to you prized paneling. You should carefully evaluate your results for possible damage to the object, either by damaging the wood itself or the glue holding it together. You can expect the paint to soften below 300 degrees.

I do not expect that there is a universal ideal paint removal system. Chemical systems can damage veneer too. In my experience, some of the worst damage occurs from overly aggressive scraper use regardless of the method used to loosen the paint.

--Richard

Author:  buzz_morris [ Wed Feb 01, 2012 9:05 pm ]
Post subject:  Re: Interior Passenger Car Paint Removal

The older veneer is thicker than what’s being made now but I’m still not sure I would want to risk scorching it with a heat gun. The interior lounge panels I worked on at the IRM went something like this.

Scrape any loose chips off being careful not to gouge anything.
Light sand with 100 grit to help “open up” any paint.
Make sure you have adequate ventilation.
Zip Strip and scrape with a dull putty knife. Rubber gloves and eye protection a must.
Repeat until most paint and varnish is off.
Using a stiff bristle paintbrush (natural not synthetic) work in another coat of stripper as you would use a scrub brush. Remove that last coat with 1 or 0 gauge steel wool. Again be careful not to scratch the work.
Use another clean bristle brush to wet and scrub small areas with lacquer thinner. Rub that off before it dries with 00 steel wool. Repeat until clean.
Let stand 24 hours before fine sanding and re-finishing.

Author:  FLO [ Wed Feb 01, 2012 10:22 pm ]
Post subject:  Re: Interior Passenger Car Paint Removal

Disclaimer: I know nothing on this topic.

But, I have noticed discussions on furniture restoration forums about how to remove paint from wood veneer furniture from the art-deco era.

Painted dresser before:

Image
Waterfall Dresser by Craftsman Furniture Restoration, on Flickr

Dresser after stripping and refinishing:

Image
Waterfall Set, Flashing by Craftsman Furniture Restoration, on Flickr

Good luck. Take your time researching ~ haste makes waste.

Author:  Bob Kutella [ Thu Feb 02, 2012 1:33 pm ]
Post subject:  Re: Interior Passenger Car Paint Removal

[quote]The air exiting a conventional heat gun may be 800 or more degrees F. While it is heating up the paint and varnish to make it soft, surface temperatures rise quickly to that of the gun exhaust. Lead melts at approximately 600 degrees [quote]

Putting on my chemistry hat, any lead in so called lead based paint is not pure elemental free lead metal so the stripping with heat will not melt it. It is an inorganic salt or lead compound that lends a lot to the colorfastness and durability of an oil based paint. And it was a pretty cheap ingredient and alternative to synthetic pigments that are now legislated.

Bob Kutella

Author:  Dave [ Thu Feb 02, 2012 2:57 pm ]
Post subject:  Re: Interior Passenger Car Paint Removal

I'm sensing a bit of a divide of misconception between those of us that have done a lot of work using many techniques, and those who may have a narrower perspective. FWIW, I've done most work on 1880-1910 passenger cars, with a bit on later 1920's steel cars with wood panelled interiors. I've found that a heat gun seems to be the fastest and least troublesome way to knock off the majority of multiple layers of anything with old school varnish underneath it - but the warnings previously posted don't apply if you move the heat gun along at the right speed, so no part of the surface gets hot enough to soften the hide glue that bonds the veneer or the paint starts vaporizing. Varnish softens at a relatively low temperature with a lot of room between it and trouble.

Once you get the feel of it, you can start at one place, heat it up, start scraping and move the scraper and the gun continuously together and strip off a 1.5 - 2" wide streak down the whole length of the car, leaving a solidified row of hard chips on the floor behind. The benefits are obvious.

Remove what you can easily for bench cleaning - it is much easier. The door and window trim, and even the vertical panels between the windows are good for this.

The discolored dirty varnish underneath is probably best solvent cleaned - and the best alternative I have found are the products used by professional furniture strippers. I think a 35 gallon drum is the smallest order....and it will clean the varnish on several cars.

It is possible that newer cars or those that were stripped and refinished and lost the old varnish somewhere along the way may react differently - so the advice to test your car is very valid. I'm ignorant of what those differences might be in terms of technique.

Your mileage may well vary. Damaged substrates are problems no matter the stripping technique you use. Be careful out there.

dave

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