A Mexican Ducati rescue and rebuild

[Airhead Wrangler]

Originally Posted by mymindsok

How about stripping the chrome off of that frame and then painting it? That shouldn't be too expensive and it isn't my $$$ anyway.

Yep, that's the plan for the frame. I'll probably go with satin black. None of the nicer chassis paints like POR15 are available here, so it might just get Krylon engine enamel. () I'm not a big fan of chrome either.

[DesmoDog]

Originally Posted by Airhead Wrangler

What's the consensus on cleaning up the cases? I see that some of the covers appear to have been chromed in the past and it's flaking off quite badly - there's more of it gone than there is remaining. I was just planning on stripping what's left off and polishing up the aluminum. Any reason not to do this? Also, is there any way of protecting the aluminum well once it's been polished? I've never owned a bike that I've felt compelled to keep pretty.

IMHO People who chrome aluminum engine covers should be kicked squarely in the nads.


from my website:
I didn't blast the case halves, there was too much to mask. For them I relied on wheel cleaner. Spray it on, hit the castings with a wire brush (by hand) and rinse. Repeat as needed. Carb cleaner can come in handy here too. I also used this method on the hubs,







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FWIW I am very leery of bead blasting engine related parts. Absolutely do not sandblast them. I know people will disagree but it's freakin aluminum for cripe sakes, you do not need to use an aggressive media on it. And i've seen a jaguar engine ruined by bead blasting. If the surface sees oil, don't spray abrasives at it. Just a little rule I follow...

Oh, and don't hit the polished parts with a steel brush!

I didn't polish the case at all after cleaning by the way. I also didn't treat it with anything. I'll let it age naturally (though there seems to be a mist of oil everywhere that protects it too!) I did however polish the sidecovers, bit not to a mirror finish.

[Airhead Wrangler]

Originally Posted by Desmodog

IMHO People who chrome aluminum engine covers should be kicked squarely in the nads.

Yeah, chroming aluminum should just be banned. I'm hoping they didn't chrome the inside of the cover where it let loose and filled the engine with chrome flakes and that's why this thing got parked after 8000 km. Let the dismantling begin... this weekend. I pulled the forward carb apart yesterday and was really encouraged by what I found. They're basically usable as-is with just a good cleaning. Not much grunge at all, the accelerator pump diaphragms were still soft, pliable and crack free, none of the jets or passageways were really clogged up to speak of. The outside could use some cleaning up, but functionally they're good to go. Woo.

[flemsmith]

Damn, makes me wanna go kick my project bike. You must have gone thru a few wire brushes.

roy

[Precis]

Some of the Ducati's covers would have been "chromed" (if you can call what the Italians did 30-odd years ago 'chrome') at the factory.
If you've got Money with a capital M, you can get stuff ceramic coated. It's microns thick but very durable (except for brake-fluid - just don't ask and we'll stay friends, okay?) and helps with heat dissapation, oil windage, etc, etc - and it's available in a variety of hip 'n cheesey colours. I did this once, I think the credit-card will be paid off sometime in 2029. High Performance Coatings is the imaginative name of the company that did it.
There's also a great treatment called GunKote - it's used in naval cannons, so should work well on a Ducati; trouble is, I think it only comes in a charcoally-browny-anthracite colour, which isn't very sexy.

Alternatively, you could try anodising back to "natural" - though not all aluminiums take anodising - and as someone previously mentioned, beware of sudden and random porosity in Italian castings.
I always like sending off cruddy parts and getting back shiny new-looking ones, wherever possible exchanging $$$ for elbow grease. These days, it's more of the elbow grease, less of the $$$.

[DesmoDog]

Originally Posted by Airhead Wrangler

..I pulled the forward carb apart yesterday and was really encouraged by what I found. ... The outside could use some cleaning up, but functionally they're good to go. Woo.

Been there, done that... twice. Not long after refurbing the stock carbs on my GT I found a pair of 32's and decided to rebuild the engine to Sport specs...

Originally Posted by flemsmith

Damn, makes me wanna go kick my project bike. You must have gone thru a few wire brushes.

You have no idea... though to be fair I did bead blast the cylinders and heads. And I put the cases in a hot tank (glorified dishwasher) too, but it only took off the oil, not the corrosion.

FWIW I used scothbrite pads on the head/cylinder of my 160. Worked pretty well. Put the cylinder in a lathe and let it spin while holding a folded sheet of scothbrite between the fins. (No hot tank or bead blaster on this one)

Originally Posted by Precis

Some of the Ducati's covers would have been "chromed" (if you can call what the Italians did 30-odd years ago 'chrome') at the factory.

That's funny. I made a comment on Italian chrome in my original reply but then deleted it before posting. For as much as I love Ducatis, they used some of the worst chrome I've ever seen...

[Airhead Wrangler]

Did you use steel or brass brushes for that? I'm experimenting with what to use on the smooth stuff, but brushes seem to be the way to go on the rougher sand cast stuff. I can't find etching wheel cleaner down here so I might just go with diluted phosphoric acid. That's the active ingredient in etching wheel cleaner, isn't it? For the smooth stuff I'm getting reasonable results starting with scotchbrite pads and then following with aluminum polish. I'll need to blast them anyway to get rid of the remaining chrome that hasn't flaked off, but finding someone around here with a blaster I can use is going to be tough. Would soda take off the remaining chrome, or do I need to use sand or beads? Walnut shell is unheard of down here.

[Wirespokes]

There's a way to remove chrome from aluminum, but don't recall how at the moment. Google it - but I think it was soaking in vinegar or something like that. Can you get phosphoric acid there???

[bk brkr baker]

I've never tried , but , have heard of Walnut shell blasting. I have seen Walnut shell media for sale somewhere.
It's hard enough to clean off rust and corosion without being able to damage joint faces.
A bonous is that if you don't get 100% of it cleaned out of your parts it 's just a non-abraisivive sludge that's left.

[Airhead Wrangler]

Originally Posted by bk brkr baker

I've never tried , but , have heard of Walnut shell blasting. I have seen Walnut shell media for sale somewhere.
It's hard enough to clean off rust and corosion without being able to damage joint faces.
A bonous is that if you don't get 100% of it cleaned out of your parts it 's just a non-abraisivive sludge that's left.

Oh I know. Believe me, I'd love to use walnut shell media, but it's just absolutely not available in Mexico, or at least where I am. I guess I could go buy a big bag of walnuts and make my own. Nah.

[Airhead Wrangler]

Originally Posted by Wirespokes

Can you get phosphoric acid there???

You betcha - by the gallon jug at the paint supply store. They sell it for stripping surfaces.

[Airhead Wrangler]

Anyone know what exactly the procedure is for hard chroming fork legs?? Obviously there's nobody near me who does this specifically, but I bet I can find a shop that hard chromes shafts for hydraulic rams. What surface finishing operations do they need to do after plating it? Do they need to strip all the existing chrome off before plating it? I have some light pitting that looks like it would just barely hit the fork seals at the top of the stroke, so it's gotta go.

Also, is it just me or is bevelheaven SUPER expensive? Their dellorto rebuild kits are $70 something bucks. I found them elsewhere for $29.95. The K&N clone pod filters they sell for $38 are available from dime city cycles for $7.95. $40 for a motion pro clutch cable? What? Am I missing something?

[anonny]

On a project past I had to remove flaking chrome from aluminum and the only way I found was a nasty sandblaster, chrome shops had no way to remove it.

Walnut blasting will make the engine castings look like it did the day it rolled out of the factory.

[DesmoDog]

Originally Posted by anonny

On a project past I had to remove flaking chrome from aluminum and the only way I found was a nasty sandblaster, chrome shops had no way to remove it.

I'm surprised chrome shops couldn't remove the old chrome? I'm also surprised any blasting media aggressive enough to remove chrome wouldn't mess up the aluminum underneath. But, I don't know much about chrome so I'll take the word of people who've actually dealt with plated aluminum! One last comment.. I was looking at a '57 Sportster project a while back and while getting advice I was told that if the sidecovers had been chromed they were essentially worhtless now...

I use stainless steel brushes, I've had brass brushes discolor a part before. I bought a couple different types of wheel cleaner. I don't rememebr the details now but they had different kinds of acid in them.

I bought new fork legs from Forking by Franks rather than deal with replating the old ones.

Bevel Heaven is expensive on some things, not so much on others. I also have to say I've only received quality stuff from them/him/Steve. For instance, the decals he sells are relatively expensive but high quality die cut and IMHO worth every penny over the cheap stuff. So you need to do your homework...

[bk brkr baker]

Way back in '87 I rebuilt a 250 Ducati Scrambler into a roadrace bike. The tubes had some chrome missing on the Marrozoccis . I took them to a local place told them what they were for and left them. When I picked them up they looked fine, but, when I tried to assemble the forks the tubes were too big by a tiny bit.
What to do? If you were as bucks down as me, you figure it out. I could get the inner into ithe outer a little so I added valve lapping paste and statered twisting. In a couple of hours the inner went all the way in and it was clean up time. I never had a seal leak and the forks worked fine. The only thing was the chrome was not shiny where the compound had been.

Maybe easier to get new tubes from Frank's ?