1933 Harley-Davidson VL Build: Preparing the Cases

[billpedalino]

I will go with what I know works and what experience has taught me. I know how to properly clean cases when glass beading is indicated and I have not ever experienced the sort term (or long term) failure that Bosch suggests, although I've read some of his other posts and he's obviously very technically astute!. I guess this a point upon which reasonable men will respectfully disagree...

[BoschZEV]

I guess this a point upon which reasonable men will respectfully disagree...

I agree. I mean, I disagree. No, what I mean is, I agree to disagree...

[sirhrmechanic]

Cheers,

Sirhr

[painterdale]

Sirhr, Now THAT'S funny! Now I can't wait for the second installment from Jim! Dale

[BigLakeBob]

Sirhr, Now THAT'S funny! Now I can't wait for the second installment from Jim! Dale

This is going to be a very long thread if we comment this much on each of his installments! Bob#6738

[BoschZEV]

This is going to be a very long thread if we comment this much on each of his installments!

Getting serious for a moment, one thing most of us probably would like to strive for is to improve restoration practices. We would like for the "quality" of restorations done today to be better than that of ones done 30 years ago. There is a tendency for people to say "that's how I was taught to do it," or "that's how I've always done it." Often they are right. How they were taught to do something 30 years ago is still the best way to do it, and so it is quite appropriate to pass that knowledge along to others. However, sometimes there is room for improvement.

Whether or not bead blasting cases is good or bad isn't the issue. We've already written enough on it here for people to decide one way or the other on that specific item. But, in a broader way, progress toward improving long standing rebuilding/restoration practices that might actually need improving comes from reasoned, respectful discussions like we've had here. Even if it does result in a very long thread...

[billpedalino]

Amen to that brother.....

[wideglide38]

I read this thread with great interest. Since having just blasted my VL trans case. I've ordered some Glyptal to seal what I can't clean away. I wanted to ask if anyone has thoughts/experiences soaking cases in acetone (to remove any remaining oil residue)? I am having the case adjuster repaired (Tig welded) and wanted to remove as much oil residue before welding. Any negative side affects from the acetone? Pros or Cons? Thoughts? I can can bake the case; but, my only oven is inside the house and I'm sure the family wouldn't appreciate the smell. Though if baking, to what temp (assuming between 300-400 degs.) and how long? I lost my baking instructions! And don't forget the drip pan.

Thanks,
William

[sirhrmechanic]

http://www.antiquemotorcycle.org/bbo...hlight=glyptal

William:

The above thread has a bunch of information on case cleaning and preparation. If you do a search on the word Glyptal, you actually get to a number of threads on aluminum case prep, cleaning and glyptal. Much more than I can re-type here easily.

The net is that Glyptal is good if you can get the cases perfectly clean and oil free. And you have to bake it (back to that indoor oven again.) Something to consider is vacuum impregnation. Not expensive for a pair of MC cases. Again, the process is described in at least one of the threads. The company Impco in Providence, RI does it and several folks here have used their services. The VI will completely seal the case without the risk of Glyptal peeling and gumming up the works, which can happen.

Mostly these days, I just use Glyptal for electrical work... covering coil windings, etc. I rarely use it in areas that will contact oil unless it is a new-production part. Even then, I prefer VI.

Cheers,

Sirhr

[wideglide38]

Sirhr,

Thank you for the info & feedback. I will definitely research IMPCO and back search the threads. I am familiar with Glyptal as my former employer used it in their electrical & electronics manufacturing processes. Though I've seen several painted cases I've had no further contact to see if there were service issues. However, I certainly do want gummed up works!

Ride safe,
William

[BoschZEV]

I wanted to ask if anyone has thoughts/experiences soaking cases in acetone (to remove any remaining oil residue)?

I'm in the middle of restoring an aluminum BSA head, which will require me to TIG weld some broken fins, and just this past week I started the cleaning process. Although oil passes through the valve areas of the head, it doesn't sit in a pool for years at a time as it might in a gearbox or set of engine cases. So, the amount of oil trapped in cracks and pores should be relatively little. Anyway, I wiped away all the obvious oil using rags, then let the head simmer on the barbeque for four hours at a gentle boil in a mixture of Dawn detergent and water, after which I left it to soak overnight before removing it. The water was pretty dirty, as would be expected, however the head looked quite clean.

Unfortunately, cleaning the head revealed that it had been painted black as some point in its life, with paint residue inaccessible between the fins. So, I then soaked it for an hour in a witches brew of MEK and trichloroethylene. There was still paint left in places after even that so I'm not done yet. But, after the solvents had evaporated from the pan the next day they had left behind a small puddle of oil (along with lots of paint residue) showing that cleaning all the oil out of even an item like this isn't easy.

The reason I used MEK and trich. instead of acetone is they are more effective degreasing solvents. However, they also are a lot more hazardous to your health. But, even with acetone, definitely do it outside and downwind from the house, not in the garage.

I could have set up a vapor degreasing operation for this. The advantage of vapor degreasing over immersing something in a pan of solvent as I did is the solvent is continuously distilled. Relatively pure solvent from a hot tank rises up, condenses on the colder part, dissolves some of the oil, and both drip back into the tank where the solvent is again distilled. This is essential for cleaning of semiconductor substrates, but is of relatively negligible advantage if the part you put in the solvent already is reasonably clean (say, after having been cleaned in detergent and rinsed).

As for baking, don't expect it to do much. The trapped oil will become less viscous at the elevated temperature and thus some of it will ooze out of pores by capillary action, but most of it will be left behind.

[BigLakeBob]

I have a friend that has used a turkey fryer several times on cases that needed cleaned before getting welded. He would boil them just like cooking a turkey but used water instead of cooking oil. I did not personally see the results, he lives in a different state, but he said they turned out very clean and were easy to weld. Any thoughts or opinions on this, has anyone else tried it? Bob Rice #6738

[sirhrmechanic]

All I'll say is that the next three turkeys had a faint flavor of thirty-weight...

Actually, this would be a safe way to go, but not sure how effective straight water boil is. That said, water is an amazing solvent and does separate oil very nicely once the oil starts flowing. The net is that it sure can't hurt.

Several people have commented on the weldability of early cases and castings and this is something our welder always comments on. They love getting our stuff in to weld. IMHO, it has to do in part with the fact that the castings were being made from virgin aluminum. Todays' castings have so many re-casts, impurities, old beer cans, etc. in them that they just aren't the same. Maybe someone with foundry or metallurgical experience can comment?

Supporting this, if I bead blast (down to the white) steel parts from some of the early/prewar cars we work on, I can leave the steel bare and unprotected for weeks before it rust blooms, especially the British prewar vehicles. Postwar British or post-26 American... and the rust blooms start within hours on unprotected metal. Same parts in many cases, same part numbers. Forgings or machinings mostly. It is uncanny. My theory is that the later you got, the less 'virgin' steel went into your parts. And in the U.S., by the mid-1920's recycling, especially in the Auto industry, had really ramped up. There were 10Million Model T's scrapped out by 1930 or so... That's a lot of recycled steel finding its way into mills.

Anyone know for sure or have thoughts in this direction? Again, this is theory on my part. Not fact... but it's very supportable by 'experiment.'

Cheers,

Sirhr

[BoschZEV]

I have a friend that has used a turkey fryer several times on cases that needed cleaned before getting welded. He would boil them just like cooking a turkey but used water instead of cooking oil. ...

If you re-read my previous post you'll see that I boiled an aluminum head in soapy water for four hours but, although it looked very clean at that point, there was still a small amount of oil that solvent later released.

Oil does not mix with straight water so, without the soap to emulsify it, boiling in water alone would have left behind nearly all of the oil (next time you come in from the garage try washing your hands using only straight tap water). However, if your friend's parts had little or no oil trapped in cracks or pores to begin with, boiling them in straight water could have removed surface dirt (which might well have had oil mixed with it, making the part look oily) and made them cleaner and easier to weld so this would have been the effect he reported to you. But, I suspect if you ask your friend for details he will report back to you that he used soapy water in his turkey fryer.

p.s. this thread started out as a build but nothing has been posted for nearly two months. Has it hit a roadblock, or is it still ongoing and the builder too busy to update it?

[wideglide38]

All good points Sirhr & Bob. I am familiar with 1,1,1 Trichlor for degreasing. A know carcinogen we had to abandon in the late '80s on our printed circuit board production line. Unfortunately those chems worked double duty - their intended application and putting one 6 feet under. Safety & caution will be applied moving forward.