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Prepping for paint . . .

Spanky

Moderator
Staff member
What's the best way to seal exposed wood before priming for paint? The lip around my body tub is wood & bondo, and I feel like it should be sealed before priming.
 
I think feather fill, 2k primer, is rated for wood. It's good for glass. It surfaces nice. It can be applied with roller, spray, etc...
 
If it's bare wood, paint it with epoxy, brush or roller, use the slow hardener to give you more time.
 
We just spray the regular primer on bare wood and then color and clear. Your color coat for single stage or clear coat if you use base/clear should seal the wood just as it supposedly seals the steel. If you use one manufacturer's primer and then another's color/clear the paints might not be compatible and could craze. Don't ask me how I know.
 
We just spray the regular primer on bare wood and then color and clear. Your color coat for single stage or clear coat if you use base/clear should seal the wood just as it supposedly seals the steel. If you use one manufacturer's primer and then another's color/clear the paints might not be compatible and could craze. Don't ask me how I know.

I have seen this happen all too often. Shops and some home builders want to cut costs and they'll use another cheaper brand of clear. With today's paint formulas many are not compatible and will want to peel away from the base. This does not show up immediately but will down the road. If you live where there is a lot of sun and heat, as I do living in Florida, you'll tend to notice this sooner than some place like northeast Ohio where I used to live. I am a firm believer in using the same brand of paint all the way through the process from primer to base to clear to insure a great lasting finish. Why, for a few dollars saved would you want to do anything less?

Jim
 
Thanks for the suggestions! I think I'm gonna just seal it with fiberglass resin, sand it and prime it.:)
 
you the man Spanky.........................
 
Thanks for the suggestions! I think I'm gonna just seal it with fiberglass resin, sand it and prime it.:)
Just remember that not all resins dry completely when exposed to air. I did a trunk lid once that appeared to be completely dry after a few days and so I shot primer on it. I set it aside and didn't get back to it for about 2 months, but when I finally got it out again the primer had crazed and had to be sanded off. I'm just glad it didn't have the final coats on it or I would have been redoing that as well.
 
Use an unwaxed general purpose polyester resin.

There's almost no reason to use that crappy waxed Bondo brand polyester resin from Home Depot.
 
Use good stuff and only put it on thin..........
 
you can't "seal" wood w/just a coating [paint , poly , whatever} just ask any wood boat owner :p... if you oncorporate some f/glass cloth into the eqation , then you have a chance of sealing it up...wood swells & shrinks w/ the weather & age/exposure & will always eventually split/crack a coating ...
 
you can't "seal" wood w/just a coating [paint , poly , whatever} just ask any wood boat owner :p... if you oncorporate some f/glass cloth into the eqation , then you have a chance of sealing it up...wood swells & shrinks w/ the weather & age/exposure & will always eventually split/crack a coating ...
Very true. You said "then you have a chance of sealing it up", emphasis on the word 'chance'.
 
Just remember that not all resins dry completely when exposed to air. I did a trunk lid once that appeared to be completely dry after a few days and so I shot primer on it. I set it aside and didn't get back to it for about 2 months, but when I finally got it out again the primer had crazed and had to be sanded off. I'm just glad it didn't have the final coats on it or I would have been redoing that as well.
You are right about resin curing. I've had issues in the past when doing General body work and the resin will bleed through, etc. Even through primer and sealer. I had a fiberglass header panel on a t bird that the exact replacement wasn't available, a mercury panel was the same except for the emblem in the top center. I had to fill a hole. I had a fit trying to get rid of it. I reworked and repainted it three times. The resin kept showing through and outlining the repair. I ended up cutting it out and using stranded bondo. Grrr! A easy three hour job took the better part of a day and a half. And yes, it was a favor for a friend....
 
Choppinczech, do you have any words of wisdom pertaining to the epoxy? I just ordered some to use on my door and jamb edges. Everything else is polyester resin and glass. Does it flow out and adhere well to existing resin based parts? I haven't personally used it before in this application.

Just that there's different viscosities for different uses. This one that I posted mixes to a consistency of like thick honey. I used some today for bonding. It wouldn't work for saturating glass. That same seller does have one that's much thinner for laminating.

The prep is the same for laying up epoxy. A good scuffed up, clean surface.

The real beauty of epoxy is the working time. Hours instead of minutes.
 

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