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Grind base material test

Posted: Tue Sep 26, 2017 9:12 pm
by rynhardt
I ordered some UHMWPE base material from Junksupply and made a few test pieces to see how well this stuff bonds.

The material I used was the Ptex Cross Sintered base 0.8/480mm CLEAR.

Did four test pieces. Two right side up, painted and unpainted. Two wrong side up, painted and unpainted.
Right side up means the sanded and corona treated side was used for bonding.Wrong side up means the structured side was used for bonding.
I used cheap rattle can paint. Epoxy paint would have been better.
We used vacuum infusion with a 50 deg C post cure. And some scrap pieces of glass and foam.

The wrong side up pieces peeled off pretty easily, as expected.
The right side up painted piece separated on the paint layer, i.e. some paint remained on the laminate and some on the base material.

The right side up unpainted piece, however, stuck like shit to a proverbial blanket. I had to peel it off with a pair of pliers and even then the base started to tear before I could peel it off much further. A sharp flat screw driver on another edge wasn't much more successful either, as pieces of glass came off with the base layer as I tried to lever it off.

Anyway, I'm duly impressed with the bonding performance. And the clarity of the bonded base is also pretty good.
I'm looking forward to using this stuff for my next board.

Re: Grind base material test

Posted: Tue Sep 26, 2017 9:48 pm
by TheJoe
Nice! I have been worried about trying to use this stuff because of bonding issues. It is not cheap either.

Re: Grind base material test

Posted: Wed Sep 27, 2017 4:14 am
by downunder
So, your plan is to make skins? How would you infuse otherwise?

Re: Grind base material test

Posted: Wed Sep 27, 2017 7:52 am
by rynhardt
Well, the plan is to use a cosmetic skin on top and the base material on the bottom. The cosmetic top skin is infused on glass to give a really gloss finish (this is done seperately).
Then the core and glass is placed between the base material and top skin, and we do the infusion. All that is left to do once it gets out of the bag is to trim the edges.

In the past we did the entire stack at one time, between two sheets of Mylar. Occasionally we would get dry spots or pinholes, which would take extra effort to fix.