Hot Rod Forum banner

Urethane On Wood

7K views 36 replies 17 participants last post by  Henry Moran 
#1 ·
I have always sprayed furniture lacquer on cabinets
and heve read lately on other forums that some guys
are spraying auto clear urethane on wood.
Does anybody know about this? Can I use my "car" clear
on wood? I have a lacquer sealer I put on first then scuff
before topcoating. Would this be a acceptable base
for the clear? My stain is an oil base so I don't think
I would try the clear over just that.
Any input is greatly appreciated.
 
#27 ·
I think you'll be fine.
Like I said, there are plenty of boats out there with spar varnish
on them going way more than a year before refinishing,
and they are exposed to the elements much worse than yours.
The key word here is "spar" varnish which is made for weather,
unlike regular varnish that is made for interior use.
 
#28 · (Edited)
Conversion Varnish

Just thought Id throw this out there.

I don't really know anything about it but I do know that it looks great on my parent's new kitchen cabinets. Conversion Varnish is a catalized finish for wood and it's supposed to last many times longer than lacquer finishes. For all I know it's just regular old cc but it's held up great to the grandkids abusing it. Maybe someone else is a little more familiar with it.

Dusty

(Part-time wood butcher)
 
#29 ·
Dusty,
I really would be scared to give much advice but I do know who can.
http://www.southernpolyurethanes.com/Photos - Clears.htm

Go to bottom left hand corner, Kim is a custom wood builder, I have seen $50,000 jobs and $8,000 end table they have done.

On colored wood coated with house of color or one I saw black she follows the perfect paint job.
The cherry was sealed and cleared with universal, bad picture because inside but look at depth on end.

Call her she would help you out as she knows more about wood paint than the makers do.
 
#30 ·
dustydirt said:
Just thought Id throw this out there.

I don't really know anything about it but I do know that it looks great on my parent's new kitchen cabinets. Conversion Varnish is a catalized finish for wood and it's supposed to last many times longer than lacquer finishes. For all I know it's just regular old cc but it's held up great to the grandkids abusing it. Maybe someone else is a little more familiar with it.

Dusty

(Part-time wood butcher)

i've used alot of conversion varnish. many companies make it. the stuff i always use is from lenmar. i must say that its the easiest stuff on the planet to apply and make look good. holds up well and can be tinted with dye or pigment. available in all sheens. i usually use satin. if i was going to do something ultra high gloss like the cabinets on barry's site i would use a polyurethane clear. used to work for a large yacht manufaturer and every piece of wood in the boat looked like that. guess thats why the were about 3mil a pop. spar varnish is good and has been used for years. it works but is somewhat old school. any boat manufaturer will be using poly clearcoat or a system containg it as the final step. our procedure was a urethane sealer with a dye went on then a clear polyester primer/filler then polyurethane clearcoat. the difference in wood is that you have grain to fill. this becomes a problem when using layers of clearcoat or varnish only because within the first 6mos there is always a little shrinkage and the grain pattern starts showing up in the final finish. its like clearcoating over 40 grit scratches on bondo. the clear polyester primer was used to fill the grain then sanded smooth and topcoated. polyesters dont shrink so you dont get that problem. for a truck bed the varnish will work fine. your not really doing a finish to the level of what i'm talking about above. as long as each board is completely sealed and there are no breaks in the finish your good to go.
 
#31 ·
jcclark said:
I have always sprayed furniture lacquer on cabinets
and heve read lately on other forums that some guys
are spraying auto clear urethane on wood.
Does anybody know about this? Can I use my "car" clear
on wood? I have a lacquer sealer I put on first then scuff
before topcoating. Would this be a acceptable base
for the clear? My stain is an oil base so I don't think
I would try the clear over just that.
Any input is greatly appreciated.
I worked some years at a furniture factory that used lacquer. It makes a beautiful finish that is easily scratched, easily damaged by heat, easily damaged by moisture but can match the appearance of the old shellac finishes while fitting the operations of a production line much better. I've never used it on anything I've built.

Polyurethanes are much tougher. You can find polyurethane finishes on wood in large public buildings. They withstand heavy traffic, even on floors. Look for those suitable for marine use or "spar" polyurethane "varnish" (they're not really a varnish, but old terms die hard).

I have no idea about the adhesion of automotive clear coat to a polyurethane wood finish. My guess is that it would do fine if provided with a little tooth (scuff the wood finish). You would need to test to see if there would be any bleed-through. You might need to thin the wood finish with the same reducer used for your clear coat to keep them compatible. I always apply at least a couple of sealer coats of thinned (3:1 and 2:1) polyurethane wood finish before a final, unthinned coat.

Since you've sprayed cabinets, you already know to allow for the expansion and contraction of wood. The metal of a car has to expand and contract with the extremes in temperature a car faces, so my guess is that the automotive clear coat already handles movement well,

You can get polyurethane wood finishes in colored or clear and matte, satin, semi-gloss or glossy finish. You can add stains to them.
 
#32 ·
wood finnish

I have used a two part Epoxy-Plus Marine Epoxy from Clark Craft on over 8 pickup beds over the last 12 years, and as far as im concerned you cant beat it. Builds to a tough and high gloss, and i mean it is strong stuff. Put it on all sides of the wood to seal good, and in about 7 years you might need to light sand and put on another coat. The ones i have done have never had to be recoated, but they have been parked in a garage when not being driven. Have never had one discolor yet. I have built over 20 cedar strip canoes using this same product and it really shows the beauty of the wood. Everyone will tell you they have the best product, but its up to you to decide.
 
#35 ·
wood finnish

They also sell a UV protector for it also. I do not use it as an adhesive. I used my regular old wood glue on my canoes. I dont think you will need to clear coat this stuff. Its kind of milky when you first lay it on, but after about 2 hrs it is as clear as glass. Plus there are no brush streaks, as it levels out great. I put on 3 coats, and sanded between each coat, as my customers wanted a glass like finnish. I have used this stuff for about every outdoor project i have built, and it still looks great. It is not cheap, but is the only thing i use.
 
#36 ·
quality parts said:
I work at Mar-K Quality Parts. We make pickup bed parts. Have been testing wood finishes for a while and you may be interested in the progress. http://www.mar-k.com/wood_finish_testing_ii.html There are several clear finishes being evaluated that are specifically designed for wood that is exposed to outdoor environments. The current test has been in place for only a few months so there are no failures yet. We post updates when failures or other notable changes occur.

I got my bed wood kit from Mar-K. They recommended a Marine Spare Varnish, so that is what I'm using. I just put the second coat on and it looks real nice. If they could pre finish the kit they would make a mint.
 
#37 ·
Henry Moran

If I can have my say here for what it's worth. Check out the photo of my truck's
dashboard, I sprayed it with durathane k , in the photo it looks like there's like
white powder on it, this is from smoothing it with fine paper, It's still got to get
the final coat. I dit about eight coats already, sanding in-between coats.

Yes you can-not apply thinners based products over wood stainers or varnishes,
the reason is that they contain oil and are minneral based, that is why you will
use terpentine to thin them with.

And seal the wood right around even inside holes if there are any.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top