Ok so last year I painted my engine using VHT silver and black paint with a clear coat. Two things happen that I would like to avoid this time around. 1. During me syncing the carbs the top end of the motor yellowed a bit which I think maybe it got too hot. 2. I did have a float stuck and spilled gas on the back end of the engine which screwed the paint up. So I have the engine ready to paint again, but this time I bought the VHT header paint since it has a higher resistance to heat and maybe it can prevent it from yellowing? Is that a correct way of thinking or should I buy actual engine paint? Also, should I put a clear coat on it in case that’s what got ate up by the gas?
Engine paint yellowing?
- Thread starter claygs750
- Start date
Barnburner
Coast to Coast
It is likely your clear coat that is yellowing not the base coat. What brand did you use? If it was me, I would consider stripping the old paint, respraying with engine enamel from VHT or Duplicolor alone (with no clear) making sure it is properly cured. You can cure it by running the motor or, for individual parts, using a steady heat source like an old oven. If that's done, the paint should be more resistant to gas. If some gas does eat the paint later, it will be easier to touch up since there's no clear on it.
High On Octane
Ton Up or Shut Up
VHT engine paint does not hold up well on air cooled engines. I sprayed my engine 2 or 3 years ago and almost all of it is flaking. I'll never use it again on a bike motor.
Trevor May
Been Around the Block
I thought VHT was supposed to be the good paint? So if it goes to crap in a couple years, then who makes a good product?
EDIT:
http://www.vhtpaint.com/products/barrelpaint/
I know, still VHT. Still?
EDIT:
http://www.vhtpaint.com/products/barrelpaint/
I know, still VHT. Still?
High On Octane
Ton Up or Shut Up
I even used acid etch primer as a base layer. But after only the 2nd or 3rd ride, it just started to bubble up, blister, pop and peel. I will probably have to have my cases soda blasted when I do my rebuild just to get them clean again. I sorely regret painting my engine with that junk.
I sandblasted my cylinders of my RD degreased them and layed a few light coats of Duplicolor Exhaust paint (flat black)on it...holds up fine this far but doesnt seem to be resistent against gasoline (even after being cured by motor heat).
Maritime
Over 10,000 Posts
I used duplicolor engine enamel on the Magna jug covers. I cured them per instructions in a toaster oven and then hit them with both gas and acetone and neither hurt the paint. They were factory painted silver, I sanded them well, washed and painted, no primer. They have not had any heat cycles yet from riding however so I can't tell you if they are going to hold up but the gas test passed. I do know that until fully cured, gas will ruin the engine paint and if you do not run the engine for the exact intervals required on the can, it never cures properly and will peel. I have had it happen on one engine and was super careful to cure the next paint job better and it has been good. I have duplicolor on the CX500 valve covers and it has 2 seasons of riding, gas and sun and they look good as new, but again, they got cured in an oven per instructions on the can. I didn't risk curing with engine heat.
Been using DupliColor ("ceramic"!) engine paint in spray bombs from the auto parts store on air cooled cylinders (and lots of other stuff) for quite a while now. Prep is glass beading and a run through the hot dishwasher only, then paint (no primer). Bake in the oven for an hour @200F and done. Not all that hard to scratch or chip, but otherwise nothing but praise. Very easy to touch up too. Not fuel proof, but pretty close - gas wipes off without a mark as long as it does not sit there for long.
