Question about Concrete Floors

[Nohone]

I am planning on having my smithy on an already built concrete floor. Nothing is going to be bolted in.

I am wondering, if I were to accidentally drop red hot steel on a concrete floor, what would happen to the concrete? I'd imagine a mark is left afterwards? Is it possible to clean this off?

[Steve Sells]

pick it up before it burns.

[jmccustomknives]

If you've got a true 'smithing shop there's going to be a lot stuff on the floor besides burns.  ;)  I seen a few that were clean, the exception to the rule.  I believe there is concrete still under the floor of my shop, though I haven't seen it in years. <_<

[MLMartin]

Depending on how new the concrete is and how large and hot the metal is, it can cause the stuff to pop and spall. I try and pick up metal that is glowing red or hotter quickly. I have concrete floors and it does not seem to be much trouble I have never had any problems.

Don't do a lot of plasma cutting or OXY/ACT cutting right over bare concrete, I have watched people do this and the molten metal splattering on the concrete makes a mess burning little holes and pocking the floor. When ever I do much cutting I just toss some old sheet metal on the floor under what ever I am cutting,

 

Mackenzie

[Nohone]

Yeah I figured I'd just have to be careful as I can to minimize dropping the steel, and if i do, I need to pick it up right fast.

I was gonna put down tarp over the concrete floor just for added protection, but then the tarp package said its flammable, so I didnt get it.

Does anything think the flammable tarp would be too unsafe?

[neg]

I've dropped hot metal on a (fibered) concrete floor. I even took my time picking it back up. Didn't do anything.

[Frosty]

Not to be mean but if you're actually considering putting a tarp on the floor to protect concrete from hot metal you're either pulling a so, so April fools joke or need to find a safer hobby.

 

If you're really worried about the damage hot iron can do to concrete I'd maybe consider putting down concrete backer board as a sacrificial barrier. Problem with putting anything on the floor is it becomes a trip hazard.

 

Pouring water on hot iron will work but you will get a face full of steam and after a short while all the steam will rust the tools and equipment in the shop.

 

I suppose you could lay a couple inches of clay on the floor and compact it hard. Of course normal folk would seriously wonder about the thinking of a person who'd cover a concrete floor in dirt.

 

You're going to drop hot iron, pick it back up in a few seconds and it's no harm no foul. Let it lay a while and the water in the concrete will boil, causing it to pop and spall. Happens to regular concrete not designed to take heat.

 

Fibercrete is very resistant to spalling under reasonable conditions, the fibreglass acts as rebar AND provides a path for steam to escape without exploding.

 

Frosty The Lucky.

[jawno]

If your worried about a concrete floor being damaged and think a tarp won't be then you should probably consider looking for a new line of work. Or at least increase your fire insurance (and read the fine print).

If this is a rental space or something and you don't want to be responsible for damages to the premises then Frosty's idea of a layer of dirt is probably your best course of action.

[Dodge]

If you are worried about damage to a concrete floor you need to find a new location, hobby, or both. Tarp idea is a bad idea; Definitely  fire hazard and potential trip hazard!! CLEAN FLOOR in a smithy??? What a concept! :wacko: I typically lay hot iron on the floor to let it cool, (the entire garage floor is genuine concrete!!)  Never had any spalling or "damage" Yes as mentioned earlier, a lot of hot metal in one spot, like torch cutting or the like or a large very hot piece left long enough it will spall and pop, but if this is Mom or Dad's favorite pristine concrete, I'd be finding another spot to smith; The smithy floor is going to get some "character" marks, I don't care what its made of or how careful you are.....ITS A BLACKSMITH SHOP!!

Sorry for the rant. putting soap box away and returning to dark (concrete) corner with pointy hat

Scott

[ianinsa]

I would hazzard a guess that at least 90% of all blacksmith shops worldwide have concrete floors. I've always had concrete floors and so far the only problem  has been dropping smoething heavy (a couple of tons)  and punching a hole in the slab,      it fixed easy enough ! 

I often  put sand on the floor just to make the underfoot area "softer" say 10mm of dry sandso when you step on something like a dropout/slug the floor has some give and is therefore softer on you.  

[Nohone]

Lol, ok ok tarp is no good.

What about a bed sheet? Or perhaps a plank of dry wood?

I hear wood absorbs heat like a champ so im just wondering.

[Jeff Lodge]

Bed sheets are fine, but they have to be at a minimum of 1000 thread count.

[Steve Sells]

and Purple too !!!

[jeremy k]

Dont forget yer Banky and yer Pillow

[Private Entrance]

Nohone, 

 

I think you're better off with just the bare concrete.  The things you mention are all flammable and are going to cause more trouble than they are worth.  I put hot pieces (black hot, not red+) on my concrete slab to cool and have had no problem with it damaging the concrete.  Biggest issue I have is loose chunks of coal/coke, clinker, or slag getting under getting ground up under foot.  Every now and again I give the area I use (I don't have the luxury of a dedicated shop) a good sweeping and a hosing down.  Other than the pen marks I have on the ground so I know where to park my anvil, you'd never know I had been there.

 

Hope this helps.

[Glenn]

If you insist on unblemished concrete, then cover the floor with plywood. It will smoke, char, and maybe burn, but should protect the floor. Adding an inch or more of sand, pea gravel, etc and keeping it raked to a uniform depth would protect the plywood.  You do not need to cover the entire shop floor, just the area(s) where hot things exist.

[Nohone]

Plywood sounds like a good idea. Thank you.

I personally do not care about the concrete floor. It's a backyard, no one lives in the backyard, and my smithy is completely out of site, in some corner. But the people living here don't want marks on the concrete. Beats me why. They're the ones who told me to get tarp, I agreed forgetting that tarp is flammable.

So yes it's kind of a retarded obstacle, but I don't mind it.

[Jeff Lodge]

Plywood sounds like a good idea. Thank you.

I personally do not care about the concrete floor. It's a backyard, no one lives in the backyard, and my smithy is completely out of site, in some corner. But the people living here don't want marks on the concrete. Beats me why. They're the ones who told me to get tarp, I agreed forgetting that tarp is flammable.

So yes it's kind of a retarded obstacle, but I don't mind it.

You probably should have led with this information... You probably would've gotten more helpful answers :)

[Avadon]

I had this same issue when i moved here. Not the worry over hot metal but the concrete itself wasn't sealed and the previous owner had made some gnarly stains working on his engine or whatever. I looked all over my area and no one had a concrete sander. I ended up sanding the whole thing on my knees with a belt sander. It's a 24x30 shop. Can we say tedious! There were also big saw cut lines that I didn't want. I ended up finding this really great stuff at Shermin Williams. It's a two component epoxy that when it sets up it's very hard, but still sandable. I squirted that into the saw cut lines and when dry I sanded over them. Then I had a very smooth (think almost aircraft hanger smooth) surface. The problem with bare concrete like that though is that anything that drops on it can/will stain it. It's like a porous sponge, just waiting to soak up dirt, oils, solvents, etc. If your concrete is not sealed, and it probably isn't, then you have the same issue.

 

After some research I found a concrete-finishing store not far from me. They sell this stuff called "Liquid Hard Ultra". I think it's about 250$ for 5 gallons of this stuff and about 2/3's of it I used on my 24'x30'shop floors. This is incredible stuff. If you can't get that name brand there are others that are fairly similar. All you have to do is make sure your concrete is clean. Scrub it with diluted muriatic acid as per instructions. Then you roll it on with a roller. Very easy application. Then there is also this white milky stuff, I'll have to get the name if your interested. But that stuff is applied over the liquid hard ultra for even more heavy duty protection.

The result are very impressive concrete floors, that are very hard. Something about the chemical actually hardens the surface of the concrete. It definitely seems more chip resistant and it's spill protection is amazing. I could pour used motor oil on the concrete and come back days later and wipe it up with no stains/penetration. For concrete floors that I inherited when I bought the place, they sure are impressive. Now hot steel will still spatter if it hits the ground but I've never noticed it burning any pock marks. Weigh that against epoxy coated floors that I used to have and it was night and day. I had so many burn marks in the epoxy floors that they looked horrible. I'll never use anything other sealed concrete as I'm very impressed with how it turned out. Took me about 6 weeks to do the whole job though. I had to move a lot of machinery as well as I didn't have anywhere else to put it. Also if you don't have any stains and the concrete is already very smooth, you could just clean the concrete and go right to sealing it.

 

If you don't think my advice will help you, open the yellow book and call some concrete slab/foundation guys and pick their brains. Most will be happy to tell you what you need without trying to fish any money out of you. I've done this before and most contractors will give you pretty good advice. After all they may have a future customer or at least someone new who will pass their name around.

I've seen guys also pour what looks like a 1/2" of sand over their floors as well, or at least a small section. Seems to work for them. For me, I cringe at the thought. I would be tracking so much sand into the house that it would be a nightmare. lol

[ThomasPowers]

The problem I have had was not with hot metal but with cold---had a couple of students drop an anvil horn first on a concrete floor knocking a pretty good spall out of it.

 

Personally given the same constraints I would move the forge area off the concrete entirely and use that for the tasks other than forging.

[Frosty]

Nahone: You're going to have to learn to ask better questions or even as helpful as folk here are we're likely to lose the desire to be very helpful. If you're not forging on the concrete then what's the problem? Sure, the property owners want their property protected from unknown people doing hazardous things. Lay something over the concrete till you've demonstrated you're not an idiot and their concrete is safe from you.

 

Still, learn to ask better questions!

 

End rant.

 

Frosty The Lucky.