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Yes David, but the fun would be in seeing the ol' lady's face when she sees her old wedding dress come out of the molasses/phosphoric mix.

David Lahey wrote:It's my RDO again so I'm having fun in the workshop today.
After chemically stripping off the black paint from this early 1970s :Bultaco: headlight shell, I noticed that there are a few solid rivets in the shell, made from aluminium.
I want to get rid of the rust before painting it. I could have taken it to a local workshop for dry blasting but decided instead to use my bucket of acid to remove the rust.
At first I was going to remove the rivets before the acid treatment, but then thought it could be fun to see how much of the rivets are left by the time the rust is gone.
Does anyone want to make a prediction of the outcome
The acid bath is diluted molasses with some added phosphoric acid. I hung the parts in the acid bath at 8/1/2023 11:30

And the rust removal was completed at 8/1/2023 21:30

Rivets are shiny and happy.

tat ty wrote:Rivets are shiny and happy.

Well they are happy to be out of the acid bath
I think the rivets would still be fine to run with but I'm very tempted to replace them.
The thing is I inherited a collection of duralumin rivets 36 years ago from my Dad and have not yet driven any of them.



The de-rusted brackets look nice already after a coat of satin epoxy paint

So this is a completely unrelated topic. Does any one know when we can expect any new Michelin X11 rear tyres in this country again? I have looked online and can`t find any over here. All the usual suspects just say out of stock! I`m in SE QLD.

Bully fanatic wrote:So this is a completely unrelated topic. Does any one know when we can expect any new Michelin X11 rear tyres in this country again? I have looked online and can`t find any over here. All the usual suspects just say out of stock! I`m in SE QLD.

Paul Arnott had some X11 rears arrive during the week and posted on facebook about it. Maybe gone by now?
Graham I just sent you a facebook PM

I bought one off Paul this morning David. Should be here next week sometime! It will be going on my M199B.

It's a wet weekend up here and I've been able to enjoy a couple of workshop therapy sessions.
These photos show some of the rear wheel/frame/swingarm/alignment I did this weekend.
I made an axle spacer for the right side of the rear wheel that takes the place of the original speedo drive. 30mm long turned out to be the magic number.
The blue thing in the hub where the spacer goes in is a ring of stiff closed cell foam fitted there to hold the spacer in place while the wheel is being put in and taken out



I then put an old 175 Campera bottom end in place for two things:
To check the chain alignment.
To see if a pre-69 magneto cover would fit this frame (no it wont). It seems that Bultaco changed the cover design to clutch-cable-on-top before they changed the frame design from single tube underneath to two tubes underneath.

The original sprocket bolts for the model 85 Alpina were fairly knocked around and I know that Bullylover has a thing about dodgy-looking fasteners so I looked in my stash of M8 x 1.25 fasteners but couldn't find anything that had a small enough head to clear the brake backing plate. The originals are 11mm AF hex which is a fairly bizarre size because M8 x 1.25 hex is usually 12 mm or 13 mm or 14 mm AF, and while flanged head M8 x 1.25 bolts can be 10 mm AF hex, the flange is too big in diameter and would look a bit weird if I machined it down in diameter.
I was ordering some other parts from Bultaco Parts Australia and found that they had the correct zinc plated 11 mm AF hex bolts for the job.

I can't believe how far the front sprocket is from the swingarm pivot point.