Do I need to seal acrylic paint on foam before glassing?
shit melts bio foam
any other suggestions to seal acrylic paint on bio foam blank before glassing? non aerosol is preferred, would suck to use bio foam, ecohesive, bamboo stringer, homemade bamboo fins , and then use an entire bottle of aerosol sealant. Like a big mac and diet coke…
Sorry
Forgot to mention - have used it on Biofoam...if it's the Homeblown variety...PU based with soya content...no problems...
Like the other guys say - do a patch test on some scrap - some paints I use - red/blue/yellow have no problem with even without sealing...just straight paint from the pot but leave plenty of drying time.
Cheers and good luck
Rich
thanks for the pic tj. Being a visual person this makes shopping easier. One question though, I am using bio foam, any worry about the sealant melting the foam?
I have endless trouble with acrylic on foam...but it's all I use as cellulose is being phased out here in the uk.
I use a similar aerosol base acrylic laquer to the one in the picture...work ok...I alos mix a bit of clear acrylic floor varnish (think they call it polish in the US) with the paint and then thin down to correct consistency with water.
Make sure you strain your paint with ladies stockings... works a treat to stop the gun blocking with thick bits or debris.
When you hot coat your rail laps before laming the deck make sure you only use minimal wax in styrene and use a cool mix - this helps prevent discolouration in certain colours...if it's still tacky give it a hotter mix over the area once the first layer has kicked...
Like I say I have heaps of problems with acrlic but I'm learning more and more every time how to fix the errors...kind of developed a love hate relationship with the stuff...good job my income dosent depend on getting boards out the door though!!!
Cheers
Rich
Pico,
I never tried it on bio foam, try a test patch with a scrap of foam. sorry
Tom
billiewillgo----------------What you are referring to is what most glassers call "crystalization". Usually ocurrs in the use of dark blue, purple , black etc. Deep base colors. I have heard that guys use acrylic floor wax or sealer as desribed above to eliminate that problem. I think if you do a search in the archives under "crystilization" you'll find some info. Lowel
If you have a habit of scraping the squeegee/spreader over the foam when you freelap, you can smear the paint, and you should seal. If your paint is under the lam only, and not on the rails where you’ll be lapping, you don’t need to seal.
One more tip if you use PE resin with UV catalyst: test the color first on a piece of blank… I had several weird results with some colors, especially if mixed. The worst: chemical reaction with too much sun giving some soft spots, the resin seem to burn! Use a well known brand too.
I never had any trouble with acrylic paint of the type that you can buy from Fiberglass Hawaii or even poster paint like Walmart sells. It's been my experience though that if you do not let it dry throughly before you lam or if you pull the squeegy to hard across the paint it can bleed. As far as UV goes; yellows; orange and reds can cause problems. Has something to do with the UV light spectrum. I used to have problems with my laminate(stickers) as some of them were screen printed in yellow. I was told to mix a small amount of UV resin catalyzed(sp) to apply the sticker and then proceed with my standard UV lay-up. It worked, preventing my laminates from "bubbling. The safest way to UV a painted blank is to use UV resin with a very small amount of catalyst. Put the laminated blank under UV light for a shorter than usaual period of time. Usually until it sets or gels. Then set it aside and let the catalyst do the rest. Lowel
Also blow off your colors after they have dried(Before you glass)! I have had a few colors (mostly black) that after the paint dried produced some flaky color spots that drifted off the paint and into the clear as the resin went down the rail with gravity.
You can get this a Wal Mart, works very well on air brushed foam, I've use it on red, blue, yellow, green and black with no runs or discoloration with poly resin regular or UV. I use an entire can on the board. Tom
By the way, how does it work with epoxy resin? (PU blank and acrylic paint job).
It works great, I do it on US Blanks and Homeblown foam all the time.
Jr. with an acrylic on foam that I just finished. This shot was prior to hot coat. Board is epoxy over poliester. Paint is rolled on with a foam roller and pin-lines are dabbed on with a foam brush. I give one light coat of clear sealer prior to laminating.
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