Die Cast Cam Cover

[D.Mac]

I have a die cast cam cover that has a small chunk chipped off the edge of one of the screw holes, and also a spot on one fin that is "worn down?"- and I would like to build it back up. Anyone have any good ideas on how to make the surface texture look original again after doing the work? Also, a PO bead blasted it.
Thanks, Doug.

[sirhrmechanic]

There are a ton of different ways you can blend in/texture new metal.

First, what metal is it? Based on your sig picture, I assume this is aluminum (not potmetal or similar?)

First task will be to arc weld up the aluminum. This is easy unless the casting is oil saturated (which can happen on castings.) If it's massively oil saturated, it may not build up well or will gob up as you try and weld it. Be careful, too, not to warp it. A good welder will handle it fine.

Then blend in the shape/size with files. I prefer that to using power tools in most cases as you are less likely to leave divots or take off too much.

The texture blending will depend on what you are trying to blend. Sand casting can be imitated with a small punch... you can scratch it with files to simulate release agent. Even doing things like whacking it with rings of keys can put old-looking scratches in it. For a die casting, which will generally be smoother, you may need to file, then use sandpaper from about 240 - 600 grit in 100 grit increments. Then polish the whole piece to the right sheen.

Send some pix of what you are trying to do and I can give you some more specific ideas. We do this stuff all the time on firewalls, engine castings, etc. Done right, you'll never see the repair. But a lot depends on the condition and cleanliness of the part to start...

Cheers, Sirhr

[exeric]

Doug, I had the same problem with the gear cover for my '51FL. It had a groove and worn fins from a sloppy brake pedal. I had a good welder build up the fins and groove, and I re-dressed it with files and block sanded it to finish. I used ScotchBrite to give it the final finish which I think simulates the original factory finish and also makes it easy to maintain a consistant look after years of road wear and washings. Unfortuantely, there are welding bubbles in a few places. I tried peening them with formed punches but didn't fix the deeper inclusions. This is Sirhr's territory so maybe he has some tricks to share. I have been thinking of getting some aluminum flux and practice gas welding on a sacrificial part. Again, Sirhr may be more familiar with this and if a gear cover is a good application for gas welding.

[jim d]

Doug
First the welds are ground down,filed and sanded to a very fine finish about a 180 or 220 grit if you are using a belt sanding wheel like the Eastwood Co sells. The idea is to obtain a satin finish similar to scotch brite which will be smoother than the sand cast you want. Use whatever tools and abrasive sheets ect. you need to obtain this finish. At this point I use pieces of a old bench grinding wheel that I have broked up to tap on the casting to simulate the sand cast finish. I have also used this method on steel castings with good results. I think that a very course wheel works best but that depends on the casting. The wheel I am using is a old foundry wheel used for grinding castings, machine shops,welding places and foundries discard there old wheels which make great donors.
Jim D

[D.Mac]

Ok, I understand welding and re-shaping the part. What I'm concerned with is the final finish. These early Pan cam covers are die-cast(smooth) aluminum. They are not textured like sand cast, nor are they polished. I figured wet sanding with progressively finer grit would be a good start. Didn't think of the scotch brite pads, that may be the answer for a final finish, it doesn't want to look polished. Any other ideas?
Thanks, Doug.

[upsrod]

Doug,
Maybe walnut shells for the final.

Rod

[Robert Luland]

Doug, There was a thread here three or four years ago that addressed what your seeking. I'll see if I still have it saved. Bob L

[Robert Luland]

Eureka! It pays to horde!
http://www.harleyhummerclub.org/members/backyardbob/

[droptopford]

Eureka! It pays to horde!
http://www.harleyhummerclub.org/members/backyardbob/

Way off topic here, but I have a quick question. Besides adding every link I would like to 'hoard' to my 'favorites', is there a good way to save and organize these things? Pretty impressive the way you were able to come up with that link.
Excellent article by the way!

[Robert Luland]

It's simple. I used to have a total mess. In my documents, I have a folder called Motorcycle stuff. In that I have sub-folders. One for every bike I own, numbers, electrics etc. I even got one called "Chris Haynes braking my balls" so I can keep track of how many times he does it every month. As far as web sites go. I just copy the address and bring it into word, paste and ad a note below it about what it's about and save it to one of the sub folders. If it's a iffy sight were the pic or address could disappear. I copy the text and the photos. This is big time true if the photos are posted though Photo-Bucket etc. The moment the author disables the link, the text might be there but the photos are gone forever. This is why I stress here that if your posting something for prosperity and learning here. Post the pictures though the forum's server. Bob L

[droptopford]

Thanks for the tips Robert. I'm just learning my way around these computers. Believe it or not, lots of what I have learned has been taught to me on the Antique Bike forums.

Clark

Hope your 'Chris H.' folder doesn't use up too much memory.

[Robert Luland]

Clark if ya got anymore questions? Just drop me a pm and I'll walk ya though it. Bob L

[Chris Haynes]

I even got one called "Chris Haynes braking my balls" so I can keep track of how many times he does it every month. . Bob L

Bob,
You really shouldn't be so sensitive.

[D.Mac]

Doug, There was a thread here three or four years ago that addressed what your seeking. I'll see if I still have it saved. Bob L

Thanks Bob,
I remember seeing this thread now that you've re-posted it, I never seem to have very good luck when I try to use the search function. I think between this method and the scotchbrite pads I should be able to make this thing look right. Thanks to all for the suggestions.
Doug.