Paint Adhesion

[joe]

I've noticed a few posts about paint adhesion problems on substrates. The latest wave of complaints are against Extira. I too, a couple of years ago, had issues with this product. My conclusion, which I have posted to adnosium, was suspicious of the waterproofing oils or whatever they use. As all of you know I began using a epoxy washes which seems to be a good step. However a few weeks ago, under a lot of pressure to get a sample sign out, I quickly coated my Extira with epoxy, primed and top coated with my latex. A couple of days later I attemped to transfer some vinyl letters and the paint lifted in a few spots. At that point my paint theory was breaking down.

Yesterday, Saturday, my good friend Doug Strickland came by to help me with a couple of 4'X10' routed panels. During the day we pulled out the afore mentioned Extira panel and gave it another set of agressive paint adhesion tests. It passed with flying colors. We couldn't get it to peal with anything short of a Sheffied Chisel. The conclusion I've come to is this. Latex has a degrated sticking ability untill it has cured. I'm thinking it sticks better with ever passing day.

One of our very successfull painting techniques is with PVC. We spray a couple of light latex coats. There again when it's fresh, it can be rolled up easily with a fingernail. I've scratch tested the paint on a couple of old PVC letters. They also showed good resistance to abresion and lifting. My current theory: Allow latex to cure down to the base.

Wouldn't it be interesting to know is this is a factor with Extira!

O yes, over the last three weeks I've called and left several messages for a technical person at Extira. They apparently know there's a problems. I not giving up. I'll wear out the phone lines working my way up to the top. I'll keep everyone posted.

J.
www.normansignco.com (http://www.normansignco.com)

[joe]

Dang it, I forgot.

Thanks Doug for your good help. He's really of great assistance no matter what we are attempting. We while the router was buzzing away we worked on some Sculpt Nouveau for the Fox Run entrance letters. At noon it was Pho Soup at a Viet. kitchen we firmed up a design for one of his clients. Those concepts were drawn on napkins and scraps of paper. Concepts should allways be done on scrap paper and thrown away immediately. This allows for a fermentation process. That seems to be the way it allways happens. Works better that way, I'm convinced.

[mikejohn]

Joe
I may have posted this before, I simply can not remember.
Not extira but MDF, not latex but enamel paint.
We found that sticking the plastic down before the paint cured was wrong. It was very cold, and we didn't wait long enough. The result was disaster.
Now we make certain it has cured, and warm the signs a little before removing the vinyl. Since then absolutely no lifting at all.

..............Mike

[rookie432]

Ahh... After all my promotions of Extira I finally got pinched. Pulled a new sheet out of the rack cut her down and put two coats of primer and two coats of SW gloss white superpaint on. Same paint I used on the last Extira project without fail. Loaded her up on the bot and ...BAM the paint just curled up on the cutter. Spent an hour cleanin all my cut edges. I could actually peel the paint right up primer and all in one pull. Almost like paint mask .
Observation..yeah not every sheet of extira is concistant. I have done plenty of these extira based panels without problem ...but...I think I'll be using the Joe Crumley patented thinned shellac technique from now on.
That would be a cool label

"Crumley Shellac."

[joe]

Howdy Bill,

Sorry to hear about the paint failure.

Since my old posts on the subject, I've also had success with thinned down epoxy. Either way you should be ok.

Extira can vary in it's ability to accept paint. I've preached, and preached on this subject. I'ts good to know I'm not out here in the wilderness alone.

We received twenty sheets today and believe in the product. It works great if used properly.

Good luck Bill,

Joe
www.normansignco.com (http://www.normansignco.com)