Acrylic Paint Thinning

I have searched all over the archives but could not find any info regarding painting on the foam instead of airbrushing. I am looking to use Delta acrylic paint on my foam before glassing. Should i use the untouched acrylic to paint to the blank or use some sort of thinner before painting it on (not airbrushing). Also, is it a good idea to go over the blank with krylon clear coat after painting to seal in the color?? Thanks. Please give any other tips you think i might need since i haven’t done this before. Thanks again.

I assume your Delta paint is water acrylic. You would thin that with water. Thin it to suit your gun. However: Water acrylic can take a long time to dry + good looking surfboard colors are a MUCH lighter color than most people realize + blanks are white = color your board with a fine mist of lightened color. The mist will dry faster and the effect will be the same as a solid, wet pale color.

hey, just thought i would let you know what i have found in doing paintings on my surfboards. first most acrylic pains can be thinned with plain good old water until you get the desired consistency. using artist quality paints as opposed to craft quality makes a big difference too. i found it best to do a few light coats of well thinned paint to get the desired colour saturation which can be worked into the irregular surface of the foam rather than a heavy coat of thicker paint as this seemed to lead to me getting air bubbles in those areas after glassing which developed while the resin cured even though there were no bubbles after i squeegeed(sp?) on the liquid resin. i also found it best to go for a design or picture that lent itself to being viewed from at least a few feet back as up close the resolution can be a bit lousy due to painting on a fairly irregular surface. probably best to just experiment a bit until you find your feel and style. hope this helps a bit. Trev

hi again just thought that i would add that you should probably skip the krylon clearcoat as this is solvent based i think and likely to dissolve into the polyester. the acrylic won’t go anywhere in the resin as it is a water based dispersion and won’t dissolve into an organic solvent (polyester resin). trev

Howzit Trev, one thing I’ve learned about water based paints is that if you thin them to much with water you lose the some of the acrylic adhesiveness and the paint can bleed. I thin with some water and acrylic paint thinner which keeps the acrylic content up and prevents any bleeding. Aloha, Kokua

Kokua is right on here. I don’t do a lot of acrylic spray jobs but lately I’ve had good luck with skipping the water thinning, instead I use an acrylic floor wax like Future (the clear stuff, thank you Herb! for this tip). I’ve found it dries very quickly and the adhesion is great. Tom S.

If I have 8 oz. of acrylic paint about how much acrylic thinner or water do i need? Thanks

Depends on the gun & tip you are using?, probably 10% is a good starting point. Thin it out just enough to get a nice even shoot, no chuncks of paint, just a nice atomized spray. -Jay

can you have problems if it isn’t thinned down enough?? bad adhesion, crystallization?

Be winter (you SAID it!)…a quick VISUAL thinning rule is that the paint should mimic the consistancy of heavy cream. NOT watery…mix with a bamboo chopstick, absolutely strain the paint for impurities and possible clogs/spatters. paint should have a “coating” effect on chopstick, not runny…sonny!

P.S…use a water trap on your compressor!

I am using a paint brush, not an airbrush…any tips?

Thin acrylic so that your paint can be sprayed with what you’re using. This may be as much as 40 percent depending on color, what kind of paint you start with, how solid a color you want, etc. As posted above, heavy cream consistency will usually work. I’ve found that my Paasche single action airbrush with #7 or #5 tip is too slow to cover large areas, so I bought an inexpensive jamb gun from Fiberglass Hawaii, and it works pretty well. But, to minimize the amount of paint wasted in overspray, for large areas I will use a rectangular piece of blue foam rubber (carpet pad, actually, but not the kind made up of many bits of multi-colored material) as a sponge brush. Alternatively you can buy a sponge brush at any hardware store. Know that dark colors (blue for example) may not be easily applied with the sponge since they will show the stroke marks. Maybe multiple coats willwork better. Yellow is almost impossible to screw up, but the darker colors require care. Experiment~!