Welding 25x5 angle to 20x20x1.6 tube

[itchy brother]

Hi all.
Im planning to fabricate a new steel frame for my ute to be able to mount 3 bucket seats side by side in the cab!
I will be using 25x25x5mm angle for the front and back rails and 20x20x1.6mm square tubing between for mounting points and bracing.
My question is what is the best way to weld the 2 different thickness materials together for a strong weld without burning holes in the 1.6mm tubing?
The angle will be sitting on top and over the ends of the tubing.
Will be using a Unimig 210 procraft series welder with argon light gas and .8mm wire.
Will post up pics if needed.
Any advice welcome.
Cheers
Joe

 

[volition82]

Rather than having the torch at a 45deg angle between the two materials I would angle the torch more towards the thicker material. If that was still causing problems I would also run the weld 0.5mm/1.mm away from where the two materials join towards the thicker material. The key is to do some test pieces before you weld the actual frame so you can get it right. Obviously you'll know if its to hot as you'll blow through but if you use the method i've mentioned about pulling away slightly from the joint of the materials I would cut up a test piece to make sure you have good penetration because if you go to far you'll have a weak weld. I've not welded a lot with .8mm just 1mm and 1.2mm but I can't see you having many problems with that small diameter wire I would think just angling the torch would do it. Once you've done a few test pieces you'll get a feel for it.

 

[itchy brother]

Thanks for the tips Volition!
Ended up finishing the main frame yesterday!
Initially i burnt a hole in 1 square tube, but turned the amps down a bit and wire speed a little too.
After that, the welding went off without too much dramas!
Still need to practice so that my welding is neater and more pleasing to thew eye though!
Some came out looking good, but others came out a bit ordinary!
Should i post pics in this thread or in the projects section?
Will have it set up today!

 

[volition82]

As they say it's practice, practice and yet more practice. For me I struggled for ages then one day it just clicked. I'm new to the forum as well so unsure on what section to post?