M38A1 Fuel tank sender and pickup mounting rings

Ivoryring · Post by **Ivoryring** » Fri Aug 14, 2020 2:37 pm

I have a used original tank that had be repaired by RENU when owned by a previous owner. The liner has failed badly. I tried aircraft stripper without success and tried to find someone locally that would acid dip it to clean out the old liner but was unable to find anyone. So I asked a local machine shop and after they laughed and told me to just replace it with a reproduction tank, they offered to bake it. At this point if I can't get the tank to work I'm thinking I'll have to just get an MD Juan one, I figured it couldn't hurt to have them try.

The oven got all the treatment off the outside of the tank, but didn't completely clean the inside.

It also managed to dismount the square cable clips and the bolt down rings for the sender and the pickup.

The tan spot in the top of this pic I thought was cement, but on taking a wirewheel to the sender hole, I found that under that 'cement' was what looks like solder.

A few questions:

1.) Were these two rings originally soldered in place or attached in some other way such as cement as I thought earlier?
2.) In any case, where is the alignment mark intended to point?

OKCM38CDN · Post by **OKCM38CDN** » Fri Aug 14, 2020 4:56 pm

Most likely what you think is solder was actually Brazing (Brass). If they used an oven they probably took the tank to approx 600 degrees, Brazing or brass melts at about 3-400 degrees. If you have access to a torch I bet they can be remounted by brazing them on... Not Propane, something with Oxygen (MAP Torch maybe)

Just my opinion...

Ivoryring · Post by **Ivoryring** » Fri Aug 14, 2020 6:15 pm

OKCM38CDN wrote:Most likely what you think is solder was actually Brazing (Brass). If they used an oven they probably took the tank to approx 600 degrees, Brazing or brass melts at about 3-400 degrees. If you have access to a torch I bet they can be remounted by brazing them on... Not Propane, something with Oxygen (MAP Torch maybe)

Just my opinion...

It isn't a problem for me to remount with either braze or solder - but the metal I'm seeing spattered is silver not yellow, hence thinking it is solder. There are brazed patches along the seams - I'm assuming these are leak fixes.