Welding and concrete?

bcp · Jan 13, 2015

Drill several small holes (1/8?) around the weld area to vent any pressure. After cooling, quickly weld them closed, or fill with epoxy.

Bruce

dragoneggs · Jan 13, 2015

bcp said:
Drill several small holes (1/8?) around the weld area to vent any pressure. After cooling, quickly weld them closed, or fill with epoxy.

Bruce

This seems like a good solution to be extra safe if you are completely closing off the concrete.

Xfaxman · Jan 13, 2015

Shield Arc said:
When this bridge project across Lake Washington was just about completed we had to remove the 24-inch pipe filled with concrete under every pier table next to the concrete columns. I got everything set up to do it, but got transferred to the Metro tunnel project down town Seattle before the work actually started. The guys used these thermal lance to cut the pipe.
https://www.youtube.com/watch?v=EV4r7OKkXmU

That brought back memories of when I worked for Calument Concrete Cutting, back in 1960!

One of the most unusual jobs we did, was cutting and removing a blast furnace at Inland Steel. I got to cut (melt) the fire brick with the iron powder oxygen lance. I have been inside an open hearth blast furnace and lived to tell about it!

Sodo · Jan 13, 2015

mikehaugen said:
at most I'm thinking maybe 3/4" long welds. Would enough heat build up from short welds like that? Do you think they will blow up in my face? Am I worrying too much?

No

No

Yes :laughing:

All the action is on the outside side of the pipe, concrete is on the inside. I predict that you can weld it as you wish. Even 1+ inch long welds, and NOTHING will happen.

mikehaugen · Jan 14, 2015

No, the ends are not capped- wide open. I'm not welding them together end to end, just going to lay about 4 of them next to each other and weld angle across them, then flip over and weld angle across again, then stand up and put pins in the angle for 3 point arms.

Thanks guys for putting my mind at ease. This all pretty much agrees with my original thinking, I just started having doubts and figured I'd ask before doing something stupid.

I see people ask stuff on here with similar situations and I feel some people have been saved from some pretty severe injuries or close calls by asking first, so it seems the smart thing to do, often there are things we overlook. Thanks again.

dragoneggs · Jan 14, 2015

mikehaugen said:
No, the ends are not capped- wide open. I'm not welding them together end to end, just going to lay about 4 of them next to each other and weld angle across them, then flip over and weld angle across again, then stand up and put pins in the angle for 3 point arms. Thanks guys for putting my mind at ease. This all pretty much agrees with my original thinking, I just started having doubts and figured I'd ask before doing something stupid. I see people ask stuff on here with similar situations and I feel some people have been saved from some pretty severe injuries or close calls by asking first, so it seems the smart thing to do, often there are things we overlook. Thanks again.

I thought it was a great question. It is stupid when you don't ask on something you have never done before. It's also great to get several opinions and tips along the way. Let's see the finished project! It's the least you can do for us now. Ha ha.

mikehaugen · Jan 14, 2015

I'll try to get to it this weekend. Right now they are laying out on the other side of some decent snow drifts. It's going to take some ambition to retrieve them! Although I've nearly gotten the tractor stuck in the snow a few times already, so I do have some incentive. Hopefully this ballast will do the trick.

Shield Arc · Jan 14, 2015

When I built that log splitter for my brother-n-law, I also built him a counterweight something like you have planned. I took a piece of 16-inch diameter fender pile that came out of the local Navy shipyard. Welded the ears on it. I had planed for him to stand it up on one end on some visqueen and fill it with concrete. I understand he hasn't done that yet.

Mike for what you have planned I wouldn't think twice about doing it. :thumbsup:

jimmysisson · Jan 14, 2015

Especially since they were cut with a torch they won't seal pressure until the weld is just about complete. IE won't mate tight anyway. I agree you'll be fine.
Jim

mikehaugen · Jan 18, 2015

Well when I went out to get them a few days ago they were frozen to the ground. We've had a warm weekend so I was able to get them. Now I just have to plan how to build this thing! They are about 300# each so manageable one at a time but once I start welding them together it won't be so easy to move them around. Wish I had a gantry!