Head, Jug and cover restoration

[RHinkel764]

Hey all: Anyone have any success in refinishing the outsides of the engine- heads, jugs and side covers? The head and jug look to be plated, possibly zinc? has anyone painted or polished these? painted them? what paint would you use for the side covers- the carb covers look to be polished. Any tips would be helpful. I'm starting the restoration of a 1967 175 DT.  Thanks  Rob

[v330123]

Rob:

When I started my 200cc BS MKII SS project, I also didn't know how to finish my engine components. I asked around, and if I asked 10 people, I swear I got 10 different answers. So I guessed my way through it. You'll see the results in the photo gallery. The project has been back on the street since January 09, and I've ridden it just over 500 miles since. I think everything still looks real nice, although I've not ridden in the rain or any other foul weather. You can see the results in the photo gallery. Mine is the one done in Krylon Classic Grey. You'll also find several "before" pictures of what the bike looked like when I got it in September 07.

I used glass bead on the top and bottom engine cases, side cases, cylinders, and cylinder heads. The cylinders on mine were purchased new, one from CPC and one from Richard Clark. Even though they were new, they were discolored from age. So I blasted the exterior of each. After blasting, the new cylinders and original heads match well. I did not coat the cylinders and heads with anything. Nor did I coat the side cases. They looked real good after the bead blast, and still look the same. I'm not gonna do anything with them until, or unless, they start to discolor significantly.

After blasting, I painted the top and bottom cases with Plasti-kote engine enamel (500 degree type). It's difficult to see, but I haven't noticed any of the paint coming off of the top or bottom cases. Also, I used some fine wet sandpaper to clean up my carb covers. Then, I used buffing wheels and compound to polish them. A professional could probably do a much better job, but I'm happy with them. I used my dremmel tool with a 3/8 diameter buffing wheel to clean up the screw head pockets in the car covers. That worked real well. I used course and fine 6" buffing wheels on my bench grinder (wheel guards removed) to buff the larger surfaces. My local Tractor Supply store had the buffing wheels and compounds. That's where I got my small blast cabinet too.

One think I will have to address, is the iron flanges that hold the head pipes to the cylinders. Mine were very rusty, so they too got a bead blast. I assume that they're supposed to be coated with something, but I was afraid that the heat on those would burn off anything I could spray on. So I left them bare. They are starting to discolor (rust) again. I supposed that's just going to happen with bare iron. Anyway, they're easy to remove and re-blast when I'm ready. Maybe I'll buy new ones some day.

I don't know if any of my methods are correct, or will last a long time. Only know that I'm satisfied with the results. I'll continue to read comments on this site to learn other opinions, and will consider those if I ever need to refinish the parts again. Good luck with your 175.

Gary

[OldSwartout]

I used glass bead on the top and bottom engine cases, side cases, cylinders, and cylinder heads.


One think I will have to address, is the iron flanges that hold the head pipes to the cylinders. Mine were very rusty, so they too got a bead blast.

Gary

I glass bead blasted the cylinders and heads on my 350 earlier this year and they cleaned up well, looking like new.  I also didn't coat them with anything, and now, after several rides in which they got wet, they are showing some white corrosion again.  I'm not really certain how to keep that from happening.  The cylinders and heads typically get to about 250-275 deg., so that's marginal for normal clear paint, but an engine clear might work.  Paint tends to insulate the surface though, so use at your own discretion on an air-cooled engine.

I also bead blasted the 350's exhaust flanges and they have quickly turned a nice reddish-brown rust color!  These were originally plated with cadmium, I believe.  I purchased one of Eastwood's home zinc plating kits some time ago, so I'm planning on trying zinc plating. However, those flanges don't really get super hot, so a coat of 500 degree silver engine paint or some header/exhaust paint should protect them pretty well if you can find it in silver.

[v330123]

OldSwartout:

Thanks for the info. I'm looking forward to hearing how your plating process works for your exhaust flanges. I'm wondering if the aluminum cylinders and heads can be made more corrosion resistant by anodizing. If so, I think that finish produced would be available in many colors, maybe even natural. I don't know if you'd have to protect the cylinder bores during such a process.

Gary

[rocketman]

 Try VHT's high heat flat aluminum on your bare aluminum parts. It looks the same as a freshly glass beaded part and doesn't seem to smudge as easy as some others. If black would work for the flanges,I have real good luck using Rustoleum bar-b-que black. It looks real good and lasts better than anything else I've seen. The color is richer and not as flat if you use it from the pint can instead of the spray balm.

[OldSwartout]

OldSwartout:

 I'm wondering if the aluminum cylinders and heads can be made more corrosion resistant by anodizing. If so, I think that finish produced would be available in many colors, maybe even natural. I don't know if you'd have to protect the cylinder bores during such a process.

Gary

I thought anodizing would work as well.  Anodizing is clear by nature; colors are added.  Anodizing is done in an acid solution and might cause a problem with bores, as the chrome is actually slightly porous (if you try to use acid to remove the aluminum from a seizure and you leave it on a long time, it will start to work under the chrome).  However, it is common and easy to mask off areas as needed.  Anodize is so thin, it wouldn't significantly affect heat transfer.

Now that I've said that, here's an article that shows how to anodize at home; but, he also says castings are not a good candidate because the impurities cause the surface to look bad. However, he shows some examples of cast horseshoes and a water pump housing. And; apparently the anodize isn't a complete protection as he says it needs sealing. Check it out, though, it sounds interesting, maybe for other parts or other restorations.     http://www.focuser.com/atm/anodize/anodize.html
This guy has a sealer for the anodize that might work on a non-anodized casting just as protection.

Eastwood has  Diamond Clear that is available in a 300 deg. aerosol and a 600 deg. 8 oz. non-aerosol.

I'm no expert on anodize; we used to have some mechanical components hard-coat anodized for the wear improvement, but that's the extent of my real-world experience.

Karl