Old Pot Metal -how to prolong life?

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration
Model T Ford Forum: Forum 2009: Old Pot Metal -how to prolong life?
Top of pagePrevious messageNext messageBottom of page Link to this message  By Ed Niedzielski on Monday, June 29, 2009 - 08:32 pm:

I have a few tired old pot metal distributors, some are badly cracked and some have some promising life left in them. Has anyone found any process to prolong the life of such old potmetal? My older and often wiser brother has suggested maybe soaking the housings in diesel fuel for a while. Any ideas or success stories out there in T Land?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce Peterson on Monday, June 29, 2009 - 08:51 pm:

Use them as patterns to have new parts made out of aluminum if that's worth it to you. This has always been a problem with 4 cylinder Chevrolets, which is why the reproduction distributors are cast from aluminum.

Unfortunately zinc castings disintigrate over time. There is little you can do about it.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ken Kopsky on Monday, June 29, 2009 - 09:27 pm:

Ditto what Royce said. The "pot metal" or die cast can be various mixtures but mostly containing Aluminum, Zinc and Copper. The combination if very atomically active and old parts get brittle and self destruct.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Darren J Wallace on Monday, June 29, 2009 - 11:00 pm:

Lead was used as a lubricant in the die cast injection mold industry years ago. Depending on how much powdered lead was used in the mold(not every shot into the mold needed repeated lubricating)would determine a century or so later how stable the pot metal mixture would stay.
Royce is right.
Antique phonograph collectors, Lionel train collectors,coin-in-slot device collectors also share your pain and frustration.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les Schubert on Tuesday, June 30, 2009 - 01:09 am:

Ed
It wasn't till late in the '20's that they realized that virtually any lead was fatal to long life of "pot metal" parts. Royce's answer about sums it up.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garnet on Tuesday, June 30, 2009 - 06:01 am:

Same problem with many of my antique radios Ed. All I've been able to do was surround the pot metal with layers of JBWeld. It won't solve the problem - it just delays the inevitable demise of the part. The warped parts I layered nearly 15 years ago are still in the same condition they were then, and work perfectly good now. Maybe they'll outlast me. If your problem is with the housing then yer gonna need lots of JBWeld, but it's really not expensive compared to having to replace the dizzy.

Regards,
Garnet


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jeff Humble on Tuesday, June 30, 2009 - 08:39 am:

Ed,
As I understand it pot metal absorbs moister and actually expands over time. Bob Scherzer who posts here from time to time has a foundry and has reproduced some pot metal pieces in aluminum. Seems the old parts that have swelled make good patterns as the pattern has to be slightly larger than the final cast part since castings shrink as they cool and the pot metal swelling and casting shrinkage are about the same. Aluminum is a much better material than pot metal, if you are looking for a long term solution for pot metal it is to replace it with aluminum.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Noel Denis Chicoine, MD on Tuesday, June 30, 2009 - 10:00 am:

My dad used to cuss pot metal just like I cuss plastic today. After several years, they both get brittle and crack and fall apart.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ed Niedzielski on Thursday, July 02, 2009 - 12:55 am:

Seems like everyone's thoughts echo what I have heard to date before. In going on a little tangent, if one was fortunate to have a distributor or another part such as an ignition switch housing that was in excellent shape, is there a way to prolong it? If the penetration of moisture accelerates the swelling of the part, then what is the best way to seal the part to head off the future potential problem?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce Peterson on Thursday, July 02, 2009 - 05:47 am:

If you were to keep pot metal parts in a vacuum there will be no oxygen to promote oxidation of the material.

Obviously that is not very convenient. The next best thing would be to powder coat or paint the part to seal it.


Add a Message


This is a public posting area. Enter your username and password if you have an account. Otherwise, enter your full name as your username and leave the password blank. Your e-mail address is optional.
Username:  
Password:
E-mail:

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration