Is welding of thin stainless steel tubing (wall thickness 0.01" - 0.02") possible ?

[pilotarix]

Hi all,

I am pretty new to "real" welding and have basicly no experience. In the past I did a few things, with electric arc welding, but that doesn't count anymore.
I use brazing with silver solder for my hobby (RC modeling), to build scale airplanes like a Piper P18, in which the fuselage is made from thin walled (wall thickness 0.01" - 0.02") stainless steel tubes. Normaly brazing with silver solder has enough strenght to keep things together, except in areas with a lot of dynamic load, like the wing and elevator hinges or the gear and especially the the engine mount. Most of the professional modell builders did some kind of workaround in those areas instead the original solution, because they don't trust a brazed connection in those areas. Most of the people which I have asked, have said categorically "no" it is not possible to weld such kind of thin tubing. But these people were not welding specialist, so maybe, while welding technology is in progress, there might be new - and affordable - possiblities nowadays.

Anyhow, attached you will see some pictures to make it easier to understand what I am talking about.
I am thankfull for any help, advice and information, even negative !

Chris

DSC_0193.jpgDSC_0256.jpgDSC_0286.jpg

[lamename]

Sure you can. But you will have to clean the solder off.

[H80N]

Chris
That fuselage is just a beautiful piece of work....

I do a lot of tig welding and the problems that I see in welding in your application would be torch handling under such a miniature environment and control of heat at very low amperages..... not saying it cannot be done... but see it as pretty challenging...
if you try the TIG route... the best torch from my viewpoint would be something like a WP-50 and for power supply.. it could even be a well regulated DC bench supply or one of the baby inverter welders like the Thermal Arc 95S or Harbor Freight 80amp types..... you will be working under 20 amps..... (something very controllacle at the lower end) this will take quite a bit of experimentation... and no small amount of skill... plus.. some dollar investment.... But it is doable if you have the determination.... not to mention eyesight and a good magnifier under your welding helmet...

http://www.weldcraft.com/products/wp-series/wp-50/

http://www.harborfreight.com/80-amp-...der-91110.html

Another approach may be using a higher silver content HARD solder with a mod of the critical joints.. possibly adding some gusseting or otherwise increasing the surface area of the joints and spreading out the stresses from point loads to distributed??

Just some thoughts..

BTW... what brand, grade, alloy of solder are you using??

[aametalmaster]

[QUOTE=H80N;278043]




Thats nice work for sure. I have 2 baby 120v 75 amp tigs that i need to get going for projects like that. That link for the little torch was perfect now to find one...Bob

[H80N]

Micro TIG is kind of a specialized field... here is an article from the Miller archive

http://www.millerwelds.com/resources...rcraft-matsuo/

here are search results from a Yahoo search

http://search.yahoo.com/search;_ylt=...0tig%20welding


One approach that may be viable for your application might be to use a micro-tig torch like a wp-50 to apply one of the high strength... high temperature brazing alloys.... that hybrid method may give you the best of both worlds....

Bob...
as far as finding them... lots of places have em... here is a sample from Baker's..... (get the rubber hose not the vinyl it is lots more flexable for just a few bucks more...)

http://www.bakersgas.com/weldcraft-wp-50-tig-torch.html

[aametalmaster]

Thanks for the link. Here is my little tig...Bob