Welding on cement block

Hvacr · Fri Mar 20, 2015 7:01 am

I searched the forum first, no luck: i'd like to bring my small inverter welder home from the shop to practice bead welding. I do not have a metal table at home, so i was thinking of setting a cement block on my black and decker work-mate table and practicing, is it safe to weld on cement blocks?

Superiorwelding · Fri Mar 20, 2015 7:26 am

Someone can give you the technical details but I would give you the answer of no. If your plate is directly on the block and your weld is over the block, the heat will cause the block to "explode" so to speak chipping away a small portion. As long as the projectile never had a chance of reaching your body you in theory would be good but I don't recommend it. Same goes if you weld directly on a concrete floor.

If you just use the block to hold the plate and are not welding directly on the brick you should be fine.
-Jonathan

Hvacr · Fri Mar 20, 2015 7:32 am

Superiorwelding wrote:Someone can give you the technical details but I would give you the answer of no. If your plate is directly on the block and your weld is over the block, the heat will cause the block to "explode" so to speak chipping away a small portion. As long as the projectile never had a chance of reaching your body you in theory would be good but I don't recommend it. Same goes if you weld directly on a concrete floor.

If you just use the block to hold the plate and are not welding directly on the brick you should be fine.
-Jonathan

Jonathan, i dont need the tech details! I thought it may be dangerous due to the amount of moisture a block holds and you confirmed my fears. I'll either haul my portable table home or get a plate just large enough and thick enough to put on the work-mate table to keep the heat away from the wooden top. Thanks.

Fri Mar 20, 2015 1:53 pm

Many a wooden table has been covered in 1/8 or 5/16 plate to protect it. If you are not oxy welding on it, or belting the hell out of it, it hold up well.

Hvacr · Fri Mar 20, 2015 4:07 pm

weldin mike 27 wrote:Many a wooden table has been covered in 1/8 or 5/16 plate to protect it. If you are not oxy welding on it, or belting the hell out of it, it hold up well.

I should have checked first, i did not know 1/8" plate would be thick enough (as long as i am using some sort of common sense). I am really digging the heck out of learning to weld.

exnailpounder · Fri Mar 20, 2015 4:55 pm

You can use any metal to cover a table. You can set your welding metal up on shimms so its actually off the table. I have used a wooden door on saw horses in a pinch. Whatever it takes.

Fri Mar 20, 2015 6:09 pm

Use the 1/8 to cover the majority, and get a bit of 3/8 for a small heavy duty section.

MinnesotaDave · Fri Mar 20, 2015 7:43 pm

Heck, I often weld on old chipboard on sawhorses when I run out of table space.

Sometimes it smokes and catches fire a little - but it goes right out again.

Cheap firebrick for a woodstove works really good too.

Hvacr · Fri Mar 20, 2015 10:38 pm

weldin mike 27 wrote:Use the 1/8 to cover the majority, and get a bit of 3/8 for a small heavy duty section.

ok I just got several nice sections (12" x 10") 1/2" plate steel today I could use as spacers.

Hvacr · Fri Mar 20, 2015 10:40 pm

[quote="MinnesotaDave"]Heck, I often weld on old chipboard on sawhorses when I run out of table space.

Ok, I am not sure I am ready to throw caution to the wind that far, when I have more control overall of my welding I wont be afraid doing that. The fire blocks are a good idea

Sat Mar 21, 2015 2:38 am

They will be spot on

Sat Mar 21, 2015 2:39 am

That means perfect

exnailpounder · Sat Mar 21, 2015 8:49 am

Heck...whats a little fire

I had a small fire on my welding table yesterday...it was a wooden block I use to prop my hand on that I was using for a shim...it got hot and caught fire but I was running an awesome bead so I couldn't stop

kept one eye on it, the other on my awesome bead.

MinnesotaDave · Sat Mar 21, 2015 10:04 am

exnailpounder wrote:Heck...whats a little fire I had a small fire on my welding table yesterday...it was a wooden block I use to prop my hand on that I was using for a shim...it got hot and caught fire but I was running an awesome bead so I couldn't stop kept one eye on it, the other on my awesome bead.

Haha! Know exactly what you mean

massacre · Sat Mar 21, 2015 12:54 pm

LMAO been there done that!

Sat Mar 21, 2015 5:41 pm

Hell, I've had the fringe around the hole in the knee of my pants catch fire while MIG welding.

I was thinking, "Can I finish this bead before it gets too hot?" I did.

Welder's curse, I suppose.

Steve S

exnailpounder · Sat Mar 21, 2015 6:27 pm

I had a rag with acetone on it catch fire while mig welding and I raced to see if I got the weld done before the rag really lit up. The pants on fire is a good one

Sat Mar 21, 2015 6:38 pm

I had sparks melt and lpg hose on the oxy, but inconveniently, an joiner on the oxy hose happened to be leaking, and caused a little lpg fire to become a flame thrower pointed at my legs. I have a very low threshold to being on fire, so I was forced to stop.

GreinTime · Sat Mar 21, 2015 7:26 pm

I tried welding my junk leg, the junk junk one of course (that's a benefit of having a cool leg guy, he gives me things to take apart so I can learn him on how they actually work.)

He had said at one point that the knee body was powder coated aluminum. So, in my infinite wisdom, I scrape a section off, and decide it's high time to weld on the thing, because I was out of other metal. So, I light up... Or not. Scrape some more off, try it again. Go full pedal at 175 amps, and boom, it works... Except for the giant eye burning smoke cloud, and the sudden urge to vomit.

Let off the pedal, wipe the piece off... Wouldn't you know, the thing is carbon fiber. Needless to say, I laughed about, called my leg guy to tell him that he was wrong, only for him to say "The clamp at the bottom and all of the hardware is aluminum, the rest is all carbon man, I thought we went over this!" apparently I wasn't paying attention that day