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Repairing "Burn Through" holes in tubing



DocChuck
07-09-2014, 01:01 AM
Well, I'm clearly a novice and in a bind, I was fixing my sons cracked go-kart frame and was on my last repair of the day when I mistakenly burned through the tubing at the site of the weld. What is the best way of fixing this? I have a flux core welder at my disposal as well but it doesn't have the best penetration.

Thanks,
DocChuck

Gadget
07-09-2014, 05:42 AM
What process are you using for the repairs? MIG, TIG, stick?

DocChuck
07-09-2014, 08:05 AM
I've been using flux-core in some areas and noticed that cracks closer to the factory welds seem to be thinner due to rust on the inside of the tubes which were never factory coated. In larger cracks with gaps, I used my stick welder. On non-vital areas of the frame, I ran test beads to prevent burn through but also was able to keep the arc lit with the stick.

Thank you for your help

DocChuck

Gadget
07-09-2014, 05:06 PM
If you're planning on trying to fill the hole with the stick welder I've found it helpful to lay an extra rod across the hole and burn it in with the live electrode. If using MIG you could lay some copper part way over the hole and carefully build up the exposed area up to the copper, then move the copper ahead. The copper should act as a heat sink preventing the hole from getting larger. If you could get some copper underneath the hole that would be ideal but with tubing it probably isn't possible.

DocChuck
07-09-2014, 07:58 PM
Thanks, that helped out just perfect….what an idea. I need to send pictures on how well that worked!!! In the future, as I get better I need to ask you about your homemade plasma utter and aluminum foundry.

Gadget
07-10-2014, 06:34 AM
Which method did you use?
As for the CNC plasma cutter and foundry I will do my best to answer any questions. One of my many back burner projects is a new electric aluminum furnace. I'm ready to start mixing the refractory but have other things that need finishing first.

DocChuck
07-11-2014, 02:16 AM
The copper I had was too big to fit inside the tube so I slit it and then overlapped the edged to close the radius a bit and maintain the curve profile as best I could to match the inside curve of the tube to be fixed. From the other end, I have a tapered rod that I could push into the slit copper forcing the copper to fit tight against the tube and then welded a piece of rod over the hole in two thicknesses and closed the gap. I overlapped the hole with the rod fragments by an inch on either side and filled in the gaps….I cleaned the weld but because it was in a non visual area, I didn't grind it flush to leave as much metal and strength in its place. It worked beautifully, I can't thank you enough for the tip. As far as the CNC cutting table, a production one is way out of budget for me. I have a pilot arc cutter…its the robotics and software that I need to tackle with all of the help available. I can't see me needing anything huge…I think three feet would be plenty for me….again…thanks. You've been a huge help.