OzVMX Forum
Clubroom => Tech Talk => Topic started by: mudguard on January 18, 2011, 01:48:16 pm
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I have a 1976 YZ80 barrel and head getting bead blasted at the moment to prepare it for painting. I previously stripped the paint off with paint stripper, then used a can of VHT to repaint it. Looked like crap as the paint bubbled when it was applied to the surface. Also was difficult to get the spray paint into the deeper parts of the fins. There may have been some chemical residue from the paint stripper reacting with the VHT product?
Can Spray Painters/Panel Shops get the result I need or do I need another product for a better finish? Dont want to stuff it up twice.
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I just use the VHT stuff. I blow as much crap off as i can with air and then I spray a heap of contact cleaner all over the part and keep blowing with air. I also try and make sure the first two coats are pretty thin and after the third I give it at least an hour before I stick it in the oven. :)
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Woodcraft satin black pot-belly stove paint, apply multiple thin coats with barrel upside down then right side up, then bake in an oven at ~100 degrees for 30 minutes. That's what I did with mine...
(http://p1.bikepics.com/pics/2010/04/19/bikepics-1955461-full.jpg)
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I used pot belly stove paint,and was happy with the result.
66 and CG,whats with the oven? I assume baking,but what advantages/results are gained by doing it that way?
Cheers,Mark.
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I used pot belly stove paint,and was happy with the result.
66 and CG,whats with the oven? I assume baking,but what advantages/results are gained by doing it that way?
Cheers,Mark.
It hardens the paint and "flashes-off" any chemical residue, if you don't do this you run the risk, when you first ride it, of making the paint sticky and any sand or tiny stones that land on it will stick and make the paint look dirty and ruff and ruin the look after it cools off (this happened on my YZ465 clutch cover)
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Don't think the "minister for war & finance" would appreciate a head & barrel in our $3000 Smeg oven. :(
Could try it when she is not home. ;D
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Just make sure you don't set the oven too hot - do that and you'll bubble the paint.. Made that mistake on a brake backing plate once... ::)
Had to strip it again and repaint it... :'(
Oh, and do it when the wife's not home so you have time to air out the oven and kitchen afterwards.... ;D
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Like all painting, cleanliness is the key. If the paint bubbles or didnt stick the part wasnt clean enough. You can never be too clean when preparing parts for painting and it is what causes most people to have trouble with good paint jobs. Ive used VHT plenty of times and ive never had probs with it sticking or being able to get inbetween the fins. Most other high temp paints will also be fine to use.
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I think my bubbling problem was caused by the weather when I painted - I'd taken great pains to clean it before I painted (tack cloth and prepsol etc), but there had been a few showers just before I painted (I was impatient ::) ), so there was probably a bit of moisture in the air.... :-\
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I use this little pie warmer. All the engine bits will fit in there (not all at once of course) and they don't use an awful lot of power or room (in the shed).
(http://i235.photobucket.com/albums/ee74/All_things_414/DSCN1390.jpg)
The 'finish' just seems so much better after baking and seems a better bond.
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Yeah cool/moist temperatures are not really good for painting but they usually wont cause bubbling either. If you get fish eyes that means you have got tiny specs of grease/oil or particles of dust or something where the paint pulls away from it.
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Magoo gave me a very good safety tip about using the oven - "do it while the wife is out otherwise you could get a black eye"
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its all good... a couple of time my old lady went to open the oven an found a bunch of bike bits in there cooking... i just think she buzzed out.
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I don't bother with those fancy name brand paints. I use $3.99 discount shop rattle cans in 'Satin Black' and bake it at 100 degrees for 20-30 minutes. I rarely use paint stripper to remove the old paint on barrels as I once had a similar bubbling problem as Mudguard due to residue stripper getting lost in the crevices. I now always get the barrel or cases blasted.
I've got a little pie oven in the shed almost the same as my dear collegue above uses. I got it at the Salvation Army for $10 and it works a treat. They're handy for warming cases prior to fitting main bearings, curing paint as we've discussed and you can whip up a nice grilled cheese sandwich during those late nights in the mancave. ;)
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and you can whip up a nice grilled cheese sandwich during those late nights in the mancave. ;)
so that is what that subtle after taste is…