I'm about 10 boards in, and helping a buddy build his first. Blank was a standard density US Blank. Airbrushed with the cheap acrylic, thinned with distilled water and given about a week to dry. Bottom lam was 6oz e-cloth and top was 2x6oz e-cloth. The bottom was laminated with silmar lam resin catalyzed to about 1.25% in pretty warm temps (~85F), kicked quickly and during curing, the blank started absorbing the resin out of the cloth. The next day, after temps had dropped to low 70s, glassed the top with about 1% mekp and had a very even wet out. Checked the board after about an hour and everything was looking good. The next morning the deck had completely absorbed the resin, just like the bottom. I tried to work in some thinned out resin, with no luck, so we just hotcoated and are hoping for the best. Am I dealing with bonding issues with the paint (I've used the same brand in the past with good results)? Is this an issue with the blank actually sucking in the resin, or is it mostly a temperature issue (glassed in similar conditions before with decent results)?
Thanks for any insight for future endeavors.
Pics are cured lam stage and then post hotcoat stage.
"kicked quickly" and draining don't seem like they would go together. And you have that one area near the nose where it turned out okay. The pic doesn't seem to be showing a bunch of pinholes, either.
My first suspect would be contamination. You stored a painted blank for a week. Maybe the cloth had something on it. Maybe you blew it off with an air compressor and something happened there. Even your mixing cup could have had some kind of residue in it.
It beats me. I'll bet that someone here has seen this before, though.
Thanks for the insight. The cups, squeegee, etc were all brand new. The fiberglass roll had never been out of the plastic wrapper until it was put on the board. The fast cure and soaking in resin didn't make sense to me. So I was leaning towards an issue with the paint. It just clicked that I used a brand new spray gun, so its possible that it was contaminated with some sort of oil from manufacturing. I sent some acetone through it first, but maybe it wasn't enough to do the trick. I'm going to experiment glassing on some off cuts of the foam with the same glass and resin and see what it is that makes it not bond. Maybe try airbrushing the foam with plain water and see what happens.
If anyone else has any ideas, they would be greatly appreciated, so I don't make the same mistake in the future. I was just getting to a confident point in my builds, and this one really took the wind out of my sails.
It's the paint. The glass job completely crystalized over it. What brand did you use?
It was "folk art" brand. The cheap $1 per bottle stuff from the craft store, thinned with distilled water. I've used a few other colors before with good results, just never purple. I've since read through people's past experiences dealing with purples. Anything I can do to avoid crystallization? Like coating with clear, etc.
911Vi9XgvWL._AC_SL1500_.jpg
You can seal the paint by squegeeing on a coat of clear resin. That way you have you'll have the glass job sticking to resin instead of to the paint. The last time I saw a board crystalize tha bad was when a customer decided to paint his own board. He use gloss acrylic enamel house paint and the whole board crystalized when it got glassed. He ended up riding it anyway. If the paint on the blank looks shinny after it dries that may crystalize. Paint that dry matte are a safer bet.
Absolutely, no doubt.
That which can be assorted without evidence was read in an illegal magazine.
Atomized suggestion to squeegee on a resin coat is great idea.
If your "experimenting" first, try thinning your paint with acrylic floor sealer (such as Future) before applying to the blank, then laminate as normal. I've done this before and it also helps the paint stick to the blank better (If your taping off designs prior to airbrushing artwork on to the blank) and taping over it won't pull off any paint.
"Secret Sauce". Aka Behr Floor and Tile Sealer works really well also as a thinning agent for paint or spackle (when spackling an EPS blank)
That which can be assorted without evidence was read in an illegal magazine.
Here is a pic of the board post paint/pre glass. The paint was a satin/matte finish, so no gloss issues. Ill try a few different material experiments, so hopefully I can pinpoint the problem. As far as the "future" floor sealer, seems like it may have changed manufacturers over time. I have some of the behr concrete sealer on hand, would that be a reasonable alternative? Thanks for the help.
20210809_141127.jpg
Yes. I know a lot of guys have sworn by Futures over the years, but I have always been wary of it. Way to much Acrylic. And; you don't want your sealer to be shiny either. Behr is a Satin.
That which can be assorted without evidence was read in an illegal magazine.
IMO Behr also goes on more evenly and just feels better to the touch.
Update:
I did some experiments to see where my issue was. I took some of the rail off cuts, along with the same 6oz glass and poly lam resin to avoid any unwanted variables.
#1- paint thinned with distilled water, dry a few days, poly lam resin with 6oz (original process)
#2- paint thinned with distilled water, dry a few days, squeegee on thin coat of lam resin and let cure, poly lam with 6oz
#3- paint thinned with behr low-lustre concrete sealer, poly lam with 6oz
#4- distilled water sprayed through airgun, poly lam with 6oz
#5- acetone sprayed through airgun, poly lam with 6oz
Conclusion: as mentioned earlier, it seems to be an issue with the paint. The compressor/airgun setup doesn't seem to be introducing any contaminants. The squeegee coat of resin pre-lam seemed to help a little, but didn't eliminate the issue. Thinning with the concrete sealer worked well. I'm sure the catalyst/temp/etc weren't exact because of the small quantities, but I tried to get as close as possible.
In the future, I would recommend against using the "folk art" brand of paint. It may just be the purple pigments, as I have used other colors in the past. But it was clearly an issue with the paint this time.
20210913_181859.jpg
20210913_174231.jpg
Honestly if I were to paint a board in a dark color I would use house paint. Flat interior house paint. I have done Turquoise and deep blues in the past with "flat" cheap interior house paint. Good results and no crystalization.
That which can be assorted without evidence was read in an illegal magazine.
I just want to thank the OP for posting this. I've heard the horror stories about crystallization for years, but never really seen a good example of it. This was pretty epic. And good job with the systematic experimentation. I know it wasn't the desired effect, but I think the snowflake look on the bottom is actually kinda cool looking.