Practice Welds and Table Protection?

[adri123]

Hi

I'm going to build my welding table in the next couple of days. It's 3mm 316 Stainless Top screwed on a 1 inch birch ply.

When doing my practice welds what's to stop the 3mm welding top from getting melted? Or should I put another piece of steel under the test piece to protect the top?

Thanks for any replies!

Adri

 

[gordon stephenson]

Just keep the actual arc away from the table top, you could also spray the stainless top with anti-spatter to stop any spatter sticking to the top.

 

[NickyEng]

My welding bench in my van is 18mm ply with a 2mm stainless top. I just run the flap disc over the Bench now and then to take the spatter off. Need to watch the heat from the job distorting the stainless plate. I just beat in back into shape with my hide hammer. I wanted to keep the weight down as I have a lot of equipment and stock too

 

[hotrodder]

If all you're working with is thinnish stainless and TIG (as per one of the other threads) then, as said, as long as you don't strike an arc directly on the table you should have zero problems. My mobile/overspill tables are skinned in thinner sheet (1 - 1.2mm steel) than Nickys and i haven't managed to locally melt them yet even with a lump of cast ally sat on them preheated to 150°C before attacking it with 200A. That sort of heat can put a few ripples in the top skin, welding thinnish stainless at 30 - 60ish A the top is rarely even gonna get warm

 

[adri123]

Thanks Rotrodder and note taken about opening more threads than needs be.

Adri

 

[hotrodder]

Wasn't a pop about starting a new threrad, more of a heads up for anyone that hadn't seen the other thread

 

[Kent]

If you put something that can hold s lot of heat down on it then you might be shocked to see a big bubble rise ups the 3 mm sheet expands locally but locked down to the ply in nearby locations
Just make sure you font do much serious heat wise because that ply can and will combust if you heat it up enough

Light box sheet and tube should go just fine though. 10 mm plate might not turn out so well

 

[Richard.]

because that ply can and will combust if you heat it up enough

For the ply underneath 3mm sheet to burst into flames Your gonna be at a minimum welding directly on the 3mm plate and even then I would expect it will smolder at the most as there will be very little oxygen to get to the smouldered area to start a combustion.
Welding parts on the top of it wont cause any issues IMO. I've known a good few people who have cladded wood in sheet to weld on as a lighter Bench and it's an acceptable top to use. In your line of work (big heavy parts been welded with high powered migs it wouldn't last long but for laying out lighter items for tig it's fine.

 

[Kent]

Yes for lighter stuff I agree but we tend to forget this sort of thing a few years down the line. It's not to be taken liberties with

Wood when you expose it to heat for a period reaches a critical point and wop! It's totally burning all at once not much smoke. Very different than what a fag end or bit of spatter might create

 

[adri123]

So. In the attached picture is the sort of thing I will be Tigging. 3mm box section and 3mm flat. On top of my 3mm table top which sits on 25mm ply.

Is this a good way to go? Or should I expect to trash the top in short order?

Thanks

 

[Richard.]

W

So. In the attached picture is the sort of thing I will be Tigging. 3mm box section and 3mm flat. On top of my 3mm table top which sits on 25mm ply.

Is this a good way to go? Or should I expect to trash the top in short order?

Thanks

View attachment 79867

with little neat jobs like that you will not trash the top. You'll be at 20-80 amps Id guess with box section thin wall and the top won't notice that heat through your welded part.

 

[Richard.]

I've used lumps of wood to keep flux contained around a sub arc pool at 600 amps and yes they smoulder away but it takes a lot more than people think before it bursts into flames. Fitted Tight under a steel top even if it was hot enough to burn the wood (highly unlikely with low/mid amp Tig) there would not be sufficient oxygen to feed the smouldering wood to generate a fire. Just my take on it.

 

[adri123]

I'm not worried about the wood. It's knackering the lovely stainless top on the table that has me concerned. If welding 3mm stainless on a 3mm stainless top I worry that it's all to easy to weld through the piece and melt the top. I guess I'll find out through experiment...

 

[Richard.]

Is there a need for the top to be stainless. It does tend to pull a bit when heated and its stronger than steel so not so easy to pull it back straight.
Don't be concerned about the nonsense you read that fab work with SS will be contaminated on a steel bench. I've never had that problem in all my years of tigging on steel benches. The key is finishing it properly. You'll need pickling paste, flap wheels and discs scotch brite etc and sit down have a good read through the stainless section with all the wonderful tips and products in Paul's threads.

 

[adri123]

have a good read through the stainless section with all the wonderful tips and products in Paul's threads

Can't see that anywhere. Is it on this forum?

TIA

Adri

 

[Richard.]

Can't see that anywhere. Is it on this forum?

TIA

Adri

Yep, go into projects and scroll down the list to stainless.

 

[skotl]

I also have a sheet-clad bench, with 3mm mild steel sheet over a wooden 30mm thick worktop.

I've never managed to weld the piece to bench but I do (due to my amateur bodging) get splatter all over the place, then I just use a flapdisk (as Nicky suggests) to clean it up.
I will use sacrificial bits of wood for some work and it does smoke (same for plasma cutting, where I'll try to use a wooden straight-edge as a guide) but I've never had anything more than charring and some smoke.

I also bought a 2KG lump of aluminium off ebay for about £15 which I use as a heat sink for smaller pieces. It gets marked, but the steel just wipes off with a glove.

 

[Kent]

I'm not worried about the wood. It's knackering the lovely stainless top on the table that has me concerned. If welding 3mm stainless on a 3mm stainless top I worry that it's all to easy to weld through the piece and melt the top. I guess I'll find out through experiment...

If your likely do something like that your going to face many more issues than the stuff you use

 

[Kent]

Is there a need for the top to be stainless. It does tend to pull a bit when heated and its stronger than steel so not so easy to pull it back straight.
Don't be concerned about the nonsense you read that fab work with SS will be contaminated on a steel bench. I've never had that problem in all my years of tigging on steel benches. The key is finishing it properly. You'll need pickling paste, flap wheels and discs scotch brite etc and sit down have a good read through the stainless section with all the wonderful tips and products in Paul's threads.

A lot depends on the shop itself. Around 88 I was working on a rebuild and extend slaughterhouse and meat processing plant In a normal dirty fab shop with grinding dust and two automated flame cutters it was an issue and obviously there was light rusting on a lot of our ms benches on cold mornings - that's contamination.
Later I worked in a pure stainless only place, no problems with guillotine blade contamination no grinding or any other ms work in the whole place was done or allowed. All stainless top benches. Top class work
No issues at all. It's all about importance and deciding if you can handle odd problems with contamination
The op says stainless only why not limit the possibly

All the best stainless shops I know three different ones come to mind doing handrails. Dairy and brewery work respectively that I know specialise for this reason. It's not that you can't more a case of if you should?

Fact is stainless ex catering benches are cheap and available and regular auctions are run of this gear. For light use perfect

 

[Shedendman]

Questions, how are you all fixing your sheet of steel/SS to the worktop/ply/wood whatever,screwed,nailed,or glued,and how are you keeping it as flat as possible?