I got an old cast valve cover for my little banger. I'm quiet happy about it, but it needs a little something in the visuel department. A little rough I would say, but it has been used for some time. It got some sand holes and some "veins" in the surface to and a little shifting in the cast sand. Can I use a little Bondo on it, or is Bondo not good on engine parts? And what is the best way to go about cleaning it? As far as my experience goes, welding in cast stuff that has spend a long period of time on oil filled inverements, soaks up a lot of oil, and becomes hard to weld. Any advice on what to do to prep it for paint, regarding oil mostly.
The only luck that I have had, and it has not been much, in regards to oil, is to beat up the part enough to reduce it to Carbon, and then re-clean as best as you can after it has cooled. It seems a little easier to weld after that. Good luck.
If you are going to paint it then JB weld is a better option that bondo. I am afraid that bondo won't handle the vibration and heat well. I am with the gimp on the clean and welding deal. it is just hard to weld old grease soaked aluminum and heat and cleaning is probably a good idea.
Beat up? Media blast? Or should that be heat up to turn oil to carbon? We can't to my knowledge get JB weld over here I know of a M***y Ferguson that had an block that got crack from frosne water. The guy who had it washed it down with degreaser and ran over it with a wite brush. Around that time Plastic padding came out, the stuff with the globe on it, and he gave it that. And to my knowledge, still no leaks. But I don't know if I still can get that.
It doesn't have to be JBWeld; any epoxy that can withstand high heat (400+F) will work. And yes, if you're going to try any welding or apply any sort of filler to it, baking the part to 'sweat' the oil out of it is a good idea. It may take more than one baking too...
I used the two part plumbers epoxy on old magneto 20 years when l was out in the middle of no where and couldnt tig it. Been working for all these years
It will only get a couple hundred degree's at the most, probably not even that hot. Bondo will work if it's not to thick. I repaired a couple valve covers that way and they lasted for years. A good quality filler primer would also work.
yes, I bake numerous alum. parts at 400 all the time and get the **** out of the pores, then use acetone to clean.
I tried welding cracks in the Morton & Brett valve cover. Nightmare. It just caused more cracks. We chased cracks in that thing for months. Bondo was finally the answer.
If it was mine I would paint it with black wrinkle and polish the ribs. Start by sanding the top with a sanding block GENTLY using the finest sandpaper that will remove most of the pitting. Possibly 240 grit. Then work down finer and finer to 1000 then polish on a buffing wheel. Clean off all grease and dirt, spray bomb it, and wipe the paint off the raised areas before it drys. Use a rag dipped in reducer wrapped tight around a finger tip to do the wiping. Don't worry if it is not perfect, when the paint is dry you can polish with metal polish which will remove the paint streaks. If you want to polish the whole cover you can do that too. Use the same technique of sanding smooth then polishing. Incidentally if you want to remove the VOLVO lettering now is the time to do it. File it down flush with the surface and file or grind the unwanted sides away.
That was my plan too, except I needed the advice to do it. I have NO plan shat so ever to remove the VOLVO lettering, because this is an rear piece, it's an unfinished or very rough cover from the rare Volvo 142 GT, 1972-1974. Its gonna be put in to my 1969 Volvo 121. That I care much about, but is OT because it got deleted after ca 30 hours. Despite they are almost unchanged from 1960-1971. Except motor/Trans update and front disc brakes. I've been thinking about painting it silver and let it harden and then paint it red. And clean the tops, because I'm not much for polishing. :wink: All good volvo engines are red. Except truck and tractors.
The other alternative is to get a buffer and polish it and let the flaws show. They are part of the originality after all. If you don't trust yourself with a buffer you can get the same result polishing by hand, it just takes longer.
Its not that I'm afraid of a buffer. I just wants to do polish more then I need to :wink: But it would look damn fine! And I like the ideer of the tops in a different color or polished.
How about sand blasting the valve cover and that should get a clean,more uniform finish then you can paint it and sand the the raised letters and ribs. This is how my rough old valve covers turned out. HRP
This is what I was talking about.... polish just the raised parts... paint the rest with black wrinkle paint which covers up a lot of flaws. The Ford and Volvo valve covers even look alike.
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