Repairing/Repainting valve covers...

[John H]

Hey folks, wanted to share what worked for me to repair my gouged valve covers.

I used that stick-form epoxy that you knead up like putty to fill in the gouges, sanded smooth with 100 grit then 000 steel wool. you may want to consider using primer and resanding to see your high and low spots better and recoat until smooth.

For the top coats I used Duplicolor Engine Enamel (DE 1615 Aluminum) from the local Kragens, and make sure you are at least 12-14 inches away, and dont worry if the first 2 coats seem a bit of a dry spray - its really easy to flow on too much paint.

http://picasaweb.google.com/johnhoecker ... 1333774642 I was surprised how well the color and gloss matched.

[goomicoo]

Does that paint come in black?

[John H]

I'm quite sure!! Your only issue may be the amount of gloss, and I found mine to be a decent satin gloss, not too shiny. Give it a whirl, didn't take me much effort, I can say that much..! Fyi, my gouges were far worse....

[goomicoo]

I'll give it a try and post the "after" pics

[ContraMoto]

On a GS I bought used, the right valve cover had deep grooves in it from a lowside slide. I used JB Weld to fill the grooves. Sanded smooth and painted with silver engine paint from hardware store. To keep it simple, I taped off the top half of the cover and only painted the bottom half where the repair was. You could not tell the difference in finish unless you got down on your knees and peered at it closely. Worked perfect!

[MoonBeemer]

Good Job on the imagination gentlemen. Impressive results.

[John H]

Er, not so fast...

I popped them back on after a few days to dry, washed the bike, fired it up and rode it a bit, and little bubbles appeared under the paint where i did the repairs. me thinks one should fire the bike up first and go for a good ride to really heat up that paint before getting it wet? Could be that the epoxy hadn't fully cured either and still needed to off-gas.

Sand, recoat upcoming...

[macx]

Engine enamel should withstand the temps on the valve cover.

Did you use any primer? If so, that needs to fully cure - like you say "gas off" before coating.

If not, did you use some i.e. 500 grit to lightly roughen the surface before you painted it? Paint needs some "profile" to stick to.

Then again it could be just as you say that the epoxy hadn't fully cured and when it was heated gave off some gas.

[ContraMoto]

I sanded the painted area with 400 first. I had read enough about attempts to refinish valve covers to not bother to remove the coating down to the bare metal. Creates huge problems...

I didn't even remove the cover to do this. Just taped off the plastic sparkwire cover and the bolts and newspapered the surrounding area. The JB Weld epoxy fix was on the cover for a week before I painted it. The paint then held up fine for the next 500 miles that I had the bike. When I sold it, I pointed out the repair to the buyer (I'm almost too into disclosure for my own good...) and he couldn't even see it when I told him where to look.

I should also mention that I repaired the BMW plastic head "protector" (which didn't) the same way. It was shredded up pretty good. I used the same JB Weld, and sanded it back to the original profiles. Then a coat of plastic primer on both of the plastic covers; sanded smooth. Lastly, a few coats of black gloss. These now look totally trick on my black R1200R; they look like painted metal. A very custom look.

[Keppelj]

There are a bunch of unknowns here, it seems to me: The compatibility of paints to each other (BMW's and the fix primer and paint), compatability of magnesium and JB and the possible porosity of the casting. I had a past life as a welder and commercial painter. Only sure-fire way do to this fix is to remove the cover, strip it and weld the scars with magnesium before resurfacing and painting.