Any tips on welding subframe to gsxr slingshot frame

[Jpich85]

I'm going to weld up the subframe I've mocked up to my frame in the next week and just wanted to ask if anyone has come across any issues or problems when welding to the gsxr slingshot 1990 frame, I think it must be cast aluminium so I know that can be a pain sometimes, I'm not an experienced welder so I'm getting my friend from work to weld it up but he hasn't done much cast aluminium, any issues with frame warpage?

I've only got an r tech 160 ac tig so I hope it's powerful enough to get good penetration on the frame.

Cheers

 

 

[Arttu]

I did that some time ago. No any special problems if I recall correctly. I didn't specifically check possible frame warpage but I would be surprised if there is any. They are relatively small welds after all. If we are talking about original style subframe tubes.

I don't remember how much current it needed but it wasn't anything extreme, maybe 120-150A. I was using aluminium-silicon filler that should be suitable for cast aluminium.

[Gixer1460]

Rule of thumb is 1A per 0.001" of material ie. 3mm tube = 0.125" = 125-130A current. The issues you may have is the cast sections will draw heat away quickly so a preheat is a good idea and at that amperage your TIG machine won't have the duty cycle for big / continuous welds (35%) so may be 4 mins welding and 10 minutes cool down, then repeat?

[Jpich85]

Thanks guys I'll give it a try, I'll make sure I prep everything well, yes I think that is my duty cycle so I'll make sure I let it cool down, I wanted a slightly bigger tig but they were so expensive I only just afford the smaller one lol

[dupersunc]

In my experience you'll struggle with a 160 amp machine. the frame is a big lump off alloy so draws a lot of heat.

Pre heating is an absolute must, and you'll need a decent heat source. 

warping shouldn't be an issue.

[Leblowski]

I have a 200 amp tig machine wich is up for frame welding al you need is a good pre heat.

[Jpich85]

Thanks again for your advice everyone, what would be the best way to pre heat? I have done a bit of that just practicing but I used a small blow torch and got a infared temperature gun to bring it up to a high temp, would a blow torch be suitable?