Hi guys, I have been working on a project for a few months and its almost in its final stages of being done. I have searched with no diffinative answer. With the plug almost complete, what type of paint do you guys usually spray on it before you make a mold out of it?
Next question is my plug has no sharp edges or any 90 degree bends on it but it does have some pretty tight turns on it should I be as worried as I am about bridging? Post pics up soon.
I use PPG Deltron DBC black base following by PPG Deltron DC3000 clear. I use Frekote FMS sealer and Frekote 770-nc as the release system.
Now the plug is made out of bondo and PVC (weird combo I know but it worked). What would happen if I primered it and them used regular rattle can paint?
You will have to use wax AND and adequate barrier of PVA to block the chemical between the single component paint the molding resin. You will want to let the paint dry for 4 or 5 days as well. I would test it first as well to make sure that it will release.
… and even then you are risking the rattle can paint to have problems. I didn’t listen to someone that told me not use rattle cans as my final coat on a plug that took me weeks to make. I learned the hard way. LOL.
so is the final verdict that ALL rattle cans should be avoided?
What type of paint is in the rattle can that makes it reactive/lousy for the final layer? what type of paint is automotive paint that is sprayed from a gun?
I too am in this kind of position with a project that I am planning. I can’t/don’t have access to a booth or other equip for quality paint…
I would like to use a semi perm over the paint because I hate wax and PVA…
I suppose I can also just do test pieces to see how they all work out but that takes time and resources and if others have learned thru exp or practice that would be really helpful.
Thanks a bunch
Way, way, way back in the day I successfully used Krylon rattle can paint on a plug. I let it dry for 4 or 5 days, used wax and PVA, and it released just fine. Krylon has since changed their chemistry so I don’t know if it still works. You cannot use a solvent based semi-perm release system, or wax alone, on a rattle can paint. Even single component auto paints that get shot from gun don’t work. If you want to use a semi you need to use a 2-part catalyzed paint or primer.
BTW, testing any unknown resin, release agent, and release surface (paint) isn’t a waste of time. It usually will save you lots of time, materials, and heart-ache. Newbies rarely test and pay dearly for it. Experienced fabricators will test any new combination to them. I would also rather test a combination myself than read about one on the internet. Each aspect of the combination is important (plug paint, release system, molding resins). Someone may recommend a plug paint that works with their molding resin and release but may not work with your chosen resins and release. Some resins don’t work with semi-permanent releases. Some plugs paints will release with just wax and polyester resin but stick with epoxy based resins. You can have a great releasing mold and switch the layup resin and have sticking either due to the release agent or the release surface incompatibility. TEST! TEST! TEST!
Thanks for all the info wyo. I agree testing is the best if you want the objective and definitive answer. Testing for a hobbiest such as myself can be SO expensive though on a relative scale of the project… depending on where and if something does end up going catastrophically wrong in lieu of testing.
One more thing, if you could, what is the make up of a 2 part paint? what is the factor that allows it to work?
Call around to your local auto paint supply shops, there is a two part spray paint and clear in a can. It has a internal bladder that you puncture and shake like crazy it works great.
The hobbyist may feel that testing is expensive but rectifying damaged moulds form lack of testing is EVEN more expensive, both financially and time-wise should it go wrong.
Honestly, I’m not exactly sure. I think that it’s the low chemical/solvent resistance of single component paints that causes the problem.
This looks like it might do the trick…
http://www.66autocolor.com/SprayMax_2K_Aerosol_Auto_Paint_p/spm-mix2k.htm
Yep spray max is what I have had good succes with
I’d still test it. 
fo sho!
so by the looks of it spray max is a one time use can because of the mix thing?
Log onto the Spray Max website. You can look at the tech. documents. It looks like you have to spray it within 48 hours at 20*C after mixing.
If you’re worried about the spray equipment investment, what about a Preval sprayer? I used that the last time I sprayed my 2k Urethane. It’s not large volume, but it did the job, and cleaned up nicely. Whatever Adam (wyowindworks) says trumps my opinion though! 
If you put the spray max in the fridge it will last 10 days . But let it reach room temp before you spray and definetly test it before you spray your part. It’s only 20$ a can and works great
Much like a cured/linked resin…2K’s have fully cured and are untouched by other induced solvents. Hence their stability.
Don’t buy aerosols if you plan on building several plugs in a year. It is not cost efficient at all.
Instead, buy an inexpensive HVLP spray gun and small used air compressor to spray quart and gallon purchases.
Places like Harbor Freight sell the cheaper eqpt. While I personally use Delvilbis/Binks/Dynabrade eqpt. for plug tools…the prior will buy you time and experience.
Since you said you used bondo and MDF, why not just coat it with a layer or two of epoxy, wetsand to 1500-2000 and then polish with polishing compounds. Chemical release on that will work a charm, no need to mess with spraying a plug, glad I avoided that one!
cheers