can you weld on concrete

[KRS]

Can you weld on a concrete floor as a base for setting the metal and welding pieces together?<br /><br />At my old dept, the guys would weld on a metal table (I think for better grounding?). I don't have a metal table and need to weld up some shelves that our 40+ mph wind last week tore apart.<br /><br />Thx all.

 

[John Hink]

Re: can you weld on concrete

it can be done however it is not recommended.The concrete will explode if it gets hot quickly.<br />In lieu of welding on cement/concrete, try laying down a sheet of plywood then place your project on it. Ground your material with the grounding cableand have at it. It can only burn if it gets too hot.Pour water on it and keep on going.

 

[Bob_VT]

Re: can you weld on concrete

Get a few fire bricks to keep stuff off concrete!

 

[Bondo]

Re: can you weld on concrete

I weld on a concrete floor All the Time,.........<br /><br />While I can't argue the points raised above,......<br />They Can be Avoided,......<br /><br />You can lay-out your materials directly on the concrete to keep everything as Flat as the floor Is,......<br /><br />And Weld on all the joints that Aren't in Direct Contact with the cement.......<br /><br />Flip it Over,+ Weld the opposite side..........<br /><br />If you're welding 2" stock,... <br />Your Live Welds would never be Closer than 2"s from the Concrete,+ It Won't Spald at that temp...... <br />Actually,......... An Inch is More Than Enough.......

 

[KRS]

Re: can you weld on concrete

Just tried welding tonight... boy that sucks! The rod kept sticking to the work even though I tried to pull it back right away after touching the metal (to "strike" an arc).<br /><br />Several rods stuck to the metal and I couldn't break them free, they turned red hot and melted. Local college doesn't have any welding classes.<br /><br />I need a mentor, a sage, a wise welder to teach me the art.

 

[islandboat]

Re: can you weld on concrete

Are you welding AC or DC? Were the rods wet? Is the setting high enough for the size of rod? Cold settings (too low setting) are harder to start but won't burn through thin metals as easy. Don't go too large with the rod size. Consider a mig welder. They can be bought for about $200 or less. The duty cycle is low but I find mig welding on thin metal is much easier and quicker that stick. You're probly welding mild steel so a mig welder would be fine.

 

[KRS]

Re: can you weld on concrete

I purchased some bar stock (1/8" thick, 1/2" wide) to practice on. The rods are the fast-fill 1/16" rods that came with the Campbell Hausfeld Arc welder 70. The rods were new out of the tube. As for AC or DC, I don't know. I plug the machine into 120V AC, but don't know if it converts. The machine uses two settings, "high" and "low", I was on low.<br /><br />I will need to make this one work, finances are tight right now.<br /><br />I was also going to try and weld some shelves that blew down, and the rod (my very first try) burned right though the metal.<br /><br />It seems to be quite difficult to strike the arc, and then get the rod far enough away to not make it stick, yet not so far it stops, all the while feeding it into the weld.

 

[islandboat]

Re: can you weld on concrete

OK, I know what you have now. Try some thick scrap metal and a high setting just to get the feel of starting the rod. Sometimes new rods have a little bit of coating on the tip that you are trying to start. I scratch the rod end on the concrete to clear the flux if that is the case. Don't stick the rod straight down into the work. Keep the rod at about a 45 degree angle to the work. You should push the rod along the metal as it puddles the molten metal, however sometimes I pull (drag) the rod if the weld is not a critical weld and the metal is thin. Practice, practice.

 

[KRS]

Re: can you weld on concrete

Roger that, I didn't have the rod at 45 degrees, and it's thin stuff.

 

[SS MAYFLOAT]

Re: can you weld on concrete

Those 110v units to me is junk. Welding small stuff is great if you already have experience. I have a little Lincoln mig that is 110v. All I use it for is stainless sheet repair. Anything over and 1/8 is really pushing the limits of a 110v unit.<br /><br />Torching on concrete is dangerous. When the flame hits the concrete, the moisture in the aggregate turns to steam causing it to explode and spawling you concrete finsish. THose little pieces can go through clothing and into the skin. Plus the lime in the concrete sets up for a nasty painful wound. BTDT and learned my lesson the hard way. Welding on concrete is okay, just don't let the metal tranfer its heat into the concrete. This also will set up for a cold weld. Best to have it spaced up off the surface to get good heat penetration.

 

[one more cast]

Re: can you weld on concrete

Try striking and arc by dragging the rod across the metal. Kind of like an airplane doing a touch and go. The reason for the metal welding table is so you don't have to ground your work piece. Just ground the table. Thats one reason anyway.

 

[KRS]

Re: can you weld on concrete

Ahhhh, that makes sense guys. Maybe a future project will be welding up a welding table... is that the chicken before the egg though... hmmmm?<br /><br />I was trying to strike the arc with a motion of approx 1/2", it sounds like I need to use 2-3" in the "swing". I'll try today.

 

[Bondo]

Re: can you weld on concrete

Ayuh,.... As Stated,.... Draw the Arc More like Striking a Match,... Rather than Slamming the rod into the work......<br /><br />And,..... Find an old pc. of Junk Steel Anything,+ Turn Up the Amps to Practice running Beads......<br /><br />Also,...... You should wander over Here, + Over Here to have a look around........

 

[jimr]

Re: can you weld on concrete

if it is a 110v stick welder I have read where people leave their welding rods in a toaster oven and keep them warm before using and they work better.like most things practice practice practice. if it is the thin sheet metal shelving you are trying to weld with a stick you are going to burn through a lot before you get the hang of it and the correct welder setting.

 

[KRS]

Re: can you weld on concrete

I messed around a little more today, all of the advice is very helpful... warm metal welds much better than cold. 45 degree angle is VERY important. I found some old 8" long 3/8" wide framing nails, and I've been welding them together and some large 3" diameter washers too. I laid a decent (beginning) bead around the washer, when it's red hot it is sooooo much easier to strike the arc again and keep going.<br /><br />The 1/16" rods go fast, it's like throwing cash into a slot machine... it never stops!

 

[whywhyzed]

Re: can you weld on concrete

I have been welding for years, and I still have a lot of trouble with those tabletop 110V units.... definitely put the rods in the oven for a while and use 2 hands... get a helmet so that you don't have to hold the little shield (that some of those units come with) with one hand...

 

[Scaaty]

Re: can you weld on concrete

Get 1/8 all purpose rods, and crank up the amps if they stick......and welding is 99% the weldor, not the welder

 

[Bondo]

Re: can you weld on concrete

Campbell Hausfeld Arc welder 70. 120V AC The machine uses two settings, "high" and "low", I was on low.

Go to your local Sears, or NAPA, or Welding Shop,+ Get yourself a 10lb. box of 6011, or 6013....In 3/32nds" Dia....... <br />They're both Easy to run mild steel rods,..... They'll give you good looking welds that are strong enough for what You're trying to do.........<br />The 6011 probably runs alittle Easier,..... The 6013 is good for when the base metal Isn't all that Clean,..........<br /><br />I'm Guessing that your machine will run 70amps. AC,...On the High setting,.... With a reasonably short duty cycle,..... <br />It'll Work Good with the 3/32nds" Rods......

 

[KRS]

Re: can you weld on concrete

rgr that, will do and report on practice.

 

[Scaaty]

Re: can you weld on concrete

Whatever ya do, don't get deep penetrating...they will REALLY stick