unsoldering the tank

[Jerry In Maine]

i have a few dinged brass tanks that i'd like to straighten out. figure i'll add these to my list of projects to be done this winter when the snow is flying. anyone unsoldered the sides off a tank, straightened out the dings then soldered it back up?

seems straightforward but just wondering. seems that whenever i think something might be easy...

[billyboy]

it can be done . but i believe it takes almost as much heat to melt the solder as the brass! there is a video of the process which was made by a member of this forum on u tube if my memory serves me correctly,

[Horsley-Anarak]

Yes

H-A

[Jerry In Maine]

found it - thanks.
i think it takes so much heat because the heat applied tries to equalize throughout the entire tank rather than just staying localized near the torch.

i looked up the temp necessary for the solder used for car radiators - its just under 500*F.

[Horsley-Anarak]

You don't need that much heat, I had the solder tested and found that from its makeup the melting range is 600-690 c.


http://www.saving-old-seagulls.co.uk/fo ... nd+removal.


If you look back through the previous posts I did report what the solder composition is.

If you want to give it a go, make sure that you have a big burner on your blowlamp.

Brass melts at 900-940 c so you should not have a problem with the brass melting.

Also make sure that you have removed every trace of petrol.

H-A

[Jerry In Maine]

i've got a small heat treating oven that might help. it'll go up to 1200F, but it sure makes the electric meter spin fast!

[Charles uk]

Jerry read the previous posts, these tanks are soldered with silver solder not soft.

[Jerry In Maine]

i read the previous. they used silver solder, i get it...

if the oven will reach temps necessary to melt silver solder it should work. i've had it to 1250F and it wasn't maxed out.

[Horsley-Anarak]

If you stick it in an oven then all of the solder joints will come apart.

You only want to get the ends off. Not the petrol outlet and cap bush, tank fixing studs and engine rest stubs.

H-A

[Jerry In Maine]

all solder will melt; that was the plan for disassembling badly damaged tanks, like those with crush damage.

those needing a hot propane burner to unsolder tank sides might look at this easily built design.

http://ronreil.abana.org/Monster_Burner.jpg

i've used this burner to melt aluminum and brass for sandcasting. from a cold start it would have a liter or so of aluminum ready to pour in 20 min or so. i would use scrap auto pistons and such as stock to be melted. fuel is taken from our bar-b-que propane bottle.

in this case the burner was inserted into a refractory lined bucket, but i think it would work well for general heating use.

[Horsley-Anarak]

Good luck.

Please post pictures of your results.

H-A