Painting a Flexible Wood Seat

Paint will naturally crack if you ask it to flex. But some automotive finishes might be able to handle minor flexing. April 21, 2008

Question
I have four seats that have been pressed out of veneer. They are very flexible. It seems the paint is cracking or separating where it flexes most. I have put a couple of coats of Magnaclaw on. Will tinted Magnamax have enough flex to use on these seats?

Forum Responses
(Finishing Forum)
From contributor L:
You are doing to paint something you shouldn't be doing to paint - flexing it. If you want paint that will have more elastic qualities, you should probably deal with an exterior paint. They are designed to withstand more expansion and contraction than an interior paint will withstand. Target makes a good exterior clear EM-9300 polycarbonate urethane. It is, however, water based.



From contributor J:
Talk to your automotive paint specialist; since they have to sell paint that is made for plastic flexible bumpers, they will have your answer. If it doesn't flex that much, I use a vinyl primer and thin coats of paint to make sure I don't get a heavy build.


From contributor D:
The finish you're looking for is called upholstery. Comes in many colors and textures.


From the original questioner:
The seats are 3/8 inch ply or veneer. There is very little flex to it.


From contributor C:
A color tint will not add flexibility to a hard clear coat to change it any degree worth while. Automotive is the way to go. Try alsacorp.com - they have flexible finishes that will work. You say it does not flex very much, but evidently enough to crack. Are you using a primer of some sort underneath it? If so, delete the primer and use pigmented finish instead and see what the results are. If it still cracks, then go to the automotive. Remember, it's the resins used in the formula along with the plasticizers that give any film its flexing properties, not the colorants.


From contributor Z:
The product they put on the plastic car bumpers to make the paint flexible is called Bull Dog. Most auto parts/paint stores stock it. Check with the manufacturer to see if it would work with your paint. If you are using a lacquer-based paint, I don't see why not. More than likely they are going to tell you they don't know, so I would buy a small spray can and try it out.


From the original questioner:
Do you think vinyl sealer would help between Magnaclaw and colored Magnamax? This job is not for a customer; it's a friend who is not fussy. But I always try to do the best job I can. I'm trying not to buy any new materials.


From contributor R:
Try the Campbell W112-19 White Vinyl Primer followed by the Magnamax topcoat. It's vinyl, so it will be a little gummy when you sand, but it will give you good adhesion and flexibility. Reduce your topcoat enough to get good flow-out and then spray two coats at about 4 wet mils and I think you should be good to go.

Personally I donít see why you canít get a standard wood finish to work in this particular application; we are not talking bumpers that have to withstand impact here. Yes, there is some flex in the piece, but I donít think it is excessive for the type of finish that you are using. There is always the possibility that the cracking could be from too much film build.



From contributor R:
Contributor J hit it right on. Sorry I missed his post.