Page 1 of 1

PMF question...latex or oil base....polyurethane or lacquer?

PostPosted: Tue Aug 08, 2017 12:23 pm
by cajundood
When i go to apply the 1/2 and 1/2 thinned to the luan....is lacquer harder than poly urethane? Then once i have the canvas glued on is it better to use latex or oil base?
thanks folks for the info :o

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Tue Aug 08, 2017 9:43 pm
by pchast
Couldn't say for better... I've had good results with Latex house paint.

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Wed Aug 09, 2017 10:38 am
by Tigris99
If your going over luan your way over thinking it.

Good exterior house paint. Use it to glue canvas down and all.

I did a test run before skinning my trailer and peeling the canvas off means taking wood off with it. No need for fancy ways of adhering canvas to luan. Only creating more work, cost, and possible problems vs just 5 gallon bucket of exterior paint.

Sent from my SM-G950U using Tapatalk

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Wed Aug 09, 2017 12:32 pm
by cajundood
Tigris99 wrote:If your going over luan your way over thinking it.

Good exterior house paint. Use it to glue canvas down and all.

I did a test run before skinning my trailer and peeling the canvas off means taking wood off with it. No need for fancy ways of adhering canvas to luan. Only creating more work, cost, and possible problems vs just 5 gallon bucket of exterior paint.

Sent from my SM-G950U using Tapatalk


just dont want the luan delaminating on me.... :cry:
it was mentioned somewhere that i should first seal all bare wood using 50% polyurethane and 50% thinner to prevent delamination.
thats why i was wondering about poly or lacquer.
glad to see i shouldn't need to use titebond 2 to adhere the canvas...could use paint. :thumbsup:
the canvas that I have has a camoflage print on it. I'd like to see that print show through as I am going with an overall camo look.
so i may have to skip the paint and use a clear spar urethane or maybe even resin $$$$

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Wed Aug 09, 2017 9:19 pm
by Tigris99
Luan will not delaminate unless it gets wet.

You have to get components that mix. And dyed camo canvas is concerning for how it will absorb anything. The point of pmf is that the canvas is pretty much saturated in paint.

And ive read that using the "mix" on luan actually causes delamination because of the glue used in it.

Preventing delamination is simple, coating the wood (and all seams) well with something that is waterproof.

Hopefully some of the other guys will chime in about what options you have with the route you want to take. If its even been tried. PMF is usually done with paint or gripper primer (for paint) to attach the canvas with more paint used to saturate fibers and finally coat outside.

The route your wanting to take could have issues with curing properly and properly adhering the canvas. Your route seems to be more commonly used over the ply without canvas.

Sent from my SM-G950U using Tapatalk

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Wed Aug 09, 2017 10:49 pm
by pchast
You can find clear tint base at most paint stores too. :thinking:
Someone had posted about using it.......

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Wed Aug 09, 2017 11:31 pm
by Tigris99
Ya Ive heard of that too. Again make sure you match types though. Latex/acrylic or oil base, dont mix the 2 types from start to finish.

Sent from my SM-G950U using Tapatalk

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Thu Aug 10, 2017 9:42 am
by tony.latham
And ive read that using the "mix" on luan actually causes delamination because of the glue used in it.


Are you sure you're not referring to the de-lamination caused by CPES?

Tony

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Fri Aug 11, 2017 7:43 am
by aggie79
I would be hesitant of using any products with high levels of solvents - such as CPES or "the mix" - with any plywood product that has very thin outside veneers. The solvents could weaken or dissolve the bond. That said, I had no issues using CPES with 3mm Russian Birch plywood.

I also would not use "the mix" if you plan to use epoxy.

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Fri Aug 11, 2017 3:00 pm
by Tigris99
Standard luan cant handle the solvents in the mix. It breaks it down about as fast as water will.

That's why birch plywood or at the least, final letter being "X" on plywood for exterior is the minimum. First the outer layer is thicker and the glue is meant to resist water and solvents. Luan is meant to be cheap underlayment, cabinet sides, things like that. Stuff with nothing more than adhesive or paint coating it. Nothing thats meant to penetrate.

I did test mineral spirits poured on luan yesturday (have scraps around still) and sure as sh**, delaminated the 4" wide piece. Since thats 50% of the mix i would say avoid that.

Oil based paint, stain, varnish (within reason, dont try to see how much it will soak up), urathane is ok as it doesn't penetrate deeply.

Luan being done with oil based paints, urethane, stuff like that which created a hard, waterproof shell is common and ok as long as you seal seams. Been a few ive found that have done that without issues. Tb2 or 3 in the seams is a great way to seal those the seams so the varnish and such dont get in. Just allow it to cure, sand off access from the face and done.

I went exterior paint/pmf for lack of maintenance required and durability against my kids and me leaning stuff against the trailer. The ones that are painted and urethaned though that ive seen are really gorgeous looking. Like the looks better than aluminum or obviously PMF.

Sent from my SM-G950U using Tapatalk

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Thu Aug 17, 2017 11:45 pm
by cajundood
Tigris99 wrote:Standard luan cant handle the solvents in the mix. It breaks it down about as fast as water will.

That's why birch plywood or at the least, final letter being "X" on plywood for exterior is the minimum. First the outer layer is thicker and the glue is meant to resist water and solvents. Luan is meant to be cheap underlayment, cabinet sides, things like that. Stuff with nothing more than adhesive or paint coating it. Nothing thats meant to penetrate.

I did test mineral spirits poured on luan yesturday (have scraps around still) and sure as sh**, delaminated the 4" wide piece. Since thats 50% of the mix i would say avoid that.

Oil based paint, stain, varnish (within reason, dont try to see how much it will soak up), urathane is ok as it doesn't penetrate deeply.

Luan being done with oil based paints, urethane, stuff like that which created a hard, waterproof shell is common and ok as long as you seal seams. Been a few ive found that have done that without issues. Tb2 or 3 in the seams is a great way to seal those the seams so the varnish and such dont get in. Just allow it to cure, sand off access from the face and done.

I went exterior paint/pmf for lack of maintenance required and durability against my kids and me leaning stuff against the trailer. The ones that are painted and urethaned though that ive seen are really gorgeous looking. Like the looks better than aluminum or obviously PMF.

Sent from my SM-G950U using Tapatalk


So for my luan.....I should NOT use "the mix" to initially seal it?? I want to seal the wood before i use the TB II to adhere my PMF to....then i want to use spar urethane over the canvas to be able to view the camo print thats on it. :roll:

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Fri Aug 18, 2017 6:14 am
by greygoos
Dont know if this can help you or not. I had suggested trying an untinted paint base over canvas. It is clear and you can see whatever color canvas is underneath. GPW said it might be worth a try but could wear down with age. Urethane presents the same problem. Another builder on here used a clear paint on his woody some years back

Re: PMF question...latex or oil base....polyurethane or lacq

PostPosted: Fri Aug 18, 2017 8:40 pm
by Tigris99
TbII wont adhere well AT ALL if you seal the wood. Literally will not stick to it. The strength comes from the glue soaking into the wood.

To even attempt what you want to do the only chance is using TBIII (titebond 3) as its waterproof.

No idea how urethane will do in direct contact with any glue. Glue doesnt accept stain well but if sanded is ok with paint.

Sent from my SM-G950U using Tapatalk