[RichardH]

Does anybody here use their table saw as a welding table?

I'm a lifelong woodworker who's finally getting into welding, and I'm trying to figure out how to overlap space. My wife isn't keen on me taking over the whole garage. Yet.

The shop is a 3rd-car bay in my garage, and it's fairly cozy (as in full); when I've got a larger project, I roll out the cars and triple the "shop". I've got a cabinet-style table saw with a large cast-iron top that seems like a good candidate to double as a welding table. All metal, no plastics; seems safe for heat.

I was thinking that I'd lay a sheet of steel on top when I'm welding - maybe around 12 gauge. That'll keep the spatter off the table saw, and give me a place to tack things down, etc. Roll up the garage door for ventilation when I weld (probably need a welding curtain to keep from flashing the neighbors).

Is this is good idea, or am I overlooking some big issue? Clearly, I've got to keep the area clear of wood and sawdust (including the trap in the saw base).

Thanks,
Richard

[AFSATCOM]

Be careful with cutting and grinding. My chop saw is the only thing started a fire on me cause it throws alot of sparks. With welding the sparks are contained to a much smaller area. One of the first things I would do personally is build a metal work table. Spatter and sparks hitting you nice woodworking equipment might not be the best thing but you can always do woodwork on a cold metal table.

[mcoe]

As long as you keep the wood working equipment clean and keep all the saw dust swept up it shouldn't be a problem. I am guilty of setting a little bench top band saw or scroll saw on my welding table when I need to cut out something for someone and then I would set the saws off the table and weld and all the saw dust that fell into the center of my welding table would be smoking. That is the only thing you need to watch out for in my opinion.

[noddybrian]

If your woodwork gear is any good & you value it - do not weld or grind anywhere near it you will ruin it - the two just don't mix - & from a safety issue just one stray spark from a grinder can find it's way into sawdust hiding out of sight & smoulder un-noticed for hours - then when you least expect it catch fire - if there is anyway possible I'd try to separate wood & metalwork.

[RichardH]

Be careful with cutting and grinding. My chop saw is the only thing started a fire on me cause it throws alot of sparks. With welding the sparks are contained to a much smaller area. One of the first things I would do personally is build a metal work table. Spatter and sparks hitting you nice woodworking equipment might not be the best thing but you can always do woodwork on a cold metal table.

Thanks, Nick.

The cabinet saw needs a lot of working room, so it's pretty much an island to itself already (between the 2nd & 3rd car bays) and clear of flammables as long as I stay good about sweeping up. I do plan on building a heavier metal table, but realistically it'll be an extension of the saw's tabletop - that's the only spot in the shop I've got room.

Also, my projects tend to cycle through phases, so I don't switch up from one day to the next - more like a few weeks at a time on one or the other. So, covering the woodworking stuff isn't out of the question (with something non-flammable).

If your woodwork gear is any good & you value it - do not weld or grind anywhere near it you will ruin it - the two just don't mix.

I'm all ears... is this because of weld spatter, or because grinding dust gets somewhere it shouldn't? I know I do need to be mindful of contaminants (grinding dust, oils) that will get into the woods and affect the finish.

Thanks,
Richard

[mcoe]

I bought a couple of the fiberglass welding blankets because we turned an old barn into a work shop and I covered up hay and grain with it and they work great for protecting stuff you don't want burnt and they are fairly inexpensive.

[Otto Nobedder]

I bought a couple of the fiberglass welding blankets because we turned an old barn into a work shop and I covered up hay and grain with it and they work great for protecting stuff you don't want burnt and they are fairly inexpensive.

I wouldn't rely on those...

I've set fires under "welding blanket" on more than one occasion, and if it's a sawdust/hay/grain fire, you might not notice until you turn in for the night and wake in panic.

Fire blanket works by absorbing heat as it melts. If the heat hits the same area often enough, the glass will actually glow. Glow or not, it will crack as it cools, opening paths for the next batch of sparks and spatter.

Keep a good, large ABC fire extinguisher. Good advice in ANY welding shop, but very important where you mix woodwork with steelwork. OSHA rules for a jobsite say, "watch for fire for 30 minutes after the hot-work is done". Good advice.

Steve S

[MinnesotaDave]

If your woodwork gear is any good & you value it - do not weld or grind anywhere near it you will ruin it - the two just don't mix - & from a safety issue just one stray spark from a grinder can find it's way into sawdust hiding out of sight & smoulder un-noticed for hours - then when you least expect it catch fire - if there is anyway possible I'd try to separate wood & metalwork.

+1

Metal work is heavy, dirty and sparks everywhere - even when you think there won't be.

Your woodwork will end up dirty and you'll be unhappy - plus your table saw will take a beating. Dings in it will scratch wood as it goes across.

If you must use the table saw, put a metal top over it and blow out all dust from inside - then you'll still be nervous sleeping.

[dhazelton]

Interesting idea though, using a table saw top and extensions bolted together. Could probably get some at a scrap yard.

[Jim51]

I have a relatively small shop and alternate between wood and metal working all the time. Everything I own is on wheels and I try to keep it as clean and clutter free as possible. As far as starting fires, rags are the worst, keep a good fire extinguisher handy.

[Bulldog2010]

I have welded in the same area as my wood working area. I know as a Firemen that I
Should not do that but sometimes we don't have the choice but to do both. Just if u have to do it like that. Please when u get done welding wait 30 min befor u leave your shop so that u can make shore that thar NO hot spots or fire. That just a good pratices to have. That could save your shop in the long run.

[Arizona SA200]

Just an idea here but what about a fab table that is on casters that you can roll in and out over top of the cabinet saw?

[Superiorwelding]

.......or I was thinking what about welding/bolting a hinge to the saw and sheet metal so that it does a 270 from vertical to horizontal. You might have to get creative but it would work.
-Jonathan

[RichardH]

Just an idea here but what about a fab table that is on casters that you can roll in and out over top of the cabinet saw?

That's creative. I was thinking in a similar direction, but more fixed - dreaming here, but something like a StrongHand fab table that's butted up to the right side of the saw. When woodworking, it's support surface for sheet goods on the table saw; when welding, their roles flip.

For the foreseeable future, I'm getting a plate of 1/4" - 1/2" aluminum to use as my welding surface, and just lay that on the table saw. Quick and relatively cheap, just not sexy.

On a related note, I'm debating how to deal with the slope of the floor (this is a residential garage). I'll get all the work surfaces flat/flush, but is it important for them to be level? I'd like them level on principal, but it means everything has to stay stationary once dialed in (not a huge deal). Question is, do you find it's useful to have a level work surface for welding?

Cheers,
Richard

[Otto Nobedder]

I far prefer a level surface, but the need depends on the precision your work requires. More detailed work is easier to measure and do from a dead-level surface.

However, don't overthink it. Build your tables with three legs, with two adjustable, and you'll fight much less to level than with a four-leg table. Only bother to adjust when it's of benefit to your task.

Two cents...

Steve S

[Superiorwelding]

Richard,
I like the 3 leg table approach. Like a camera tripod it would be quick and easy to adjust. Of course you can go hog wild in any other table design, but this one seems pretty easy. My welding tables all have 3/4" nuts welded into the legs, so when/if the need arises we simply throw bolts in and level them. This also helps to raise the tables for certain projects. I like my tables higher than most and my table has the bolts in.
For our floor it is 1/8" +/- over 20'. If I remember right it was 1/2" out over 300'. It was very important for us to have a level floor for our projects. We also built saw horses out of beams that are 1/16" +/- to each other. We even use a transit to check our work. This way what ever we start working off of we know reasonably that we have a good base.
However come to my garage floor and well it is a mess. I have the same things here. Weld tables with bolts that I can easily level.
Steve hit it on the head, if precision it something you require, it is better to set something up right now, than to wish you would have.

Three cents
-Jonathan

[Otto Nobedder]

For our floor it is 1/8" +/- over 20'. If I remember right it was 1/2" out over 300'. It was very important for us to have a level floor for our projects...
Jonathan

That was exactly why I suggested the three-leg approach... The floor in this fellow's shop likely slopes to a floor drain, from his description, and a three-legged mobile table is far easier to level on a "dished" surface.

I wish the circus I work for would level the floors to 1/8" in 20'

Steve S

[Superiorwelding]

I have been wanting to make a circle welding table for quite some time, maybe I will give the three leg approach a go.

...let me tell you, you become very spoiled when your floor is level. Now if I can convince the wife to let me re-poor my garage I would be just as spoiled.

[RichardH]

Thanks, guys. Yeah, around here the attached garages start 3" lower than the interior slab, then slope toward the exterior for drainage and fumes. Mine slopes at least 1" over 15'.

I once did work for a semiconductor equipment maker, and I recall their floor was supposed to be within 1/8" overall - they ground the high spots and then poured a low-viscosity epoxy when they built the factory. This was so they could move heavy equipment by floating it on a layer of air - the frames were designed with air compressor jets in the bottom, like an inverted air hockey table. Pretty cool, considering their machines weighed over a ton, yet could be pushed around easily.

For the handful of times I've rearranged my big gear in the last 20 years here, you're right that I should just level it and be done. The 3-legged approach sounds practical.

Cheers,
Richard

[Arizona SA200]

I also use the nut in the table legs with a bolt for adjustment. My shop floor is probably within an 1/8 to 3/16 but its only a 30 by 50. Only a 1/2 inch out over 300 feet is great.

[weldin mike 27]

Thats the way they move locomotives in the GE factory, Almost 200 tonnes that you can push with your little finger.

[Otto Nobedder]

In a plastics shop in 1991, I built a system to trim very large parts using the "inverted air-hockey" system, enabling one person to easily manipulate the part (and the heavy router-guide) against a horizontal router in a sliding fixture. They were stunned at how effortless and safe it was. They were so impressed, they gave me a whole 25 cent/hr raise!

That's why I wish they'd level and resurface the floors at work. I could manipulate these 24 ton beasts so much easier...

Steve S

[RichardH]

In a plastics shop in 1991, I built a system to trim very large parts using the "inverted air-hockey" system, enabling one person to easily manipulate the part (and the heavy router-guide) against a horizontal router in a sliding fixture. They were stunned at how effortless and safe it was. They were so impressed, they gave me a whole 25 cent/hr raise!

Now, that's a clever idea too. I wonder how easily that could be incorporated into, say, your everyday table saw, router table, etc. for working with sheet goods.

Any idea what the CFM requirement was for your rig? I'm curious how big of a compressor it takes vs. the weight of the object (assuming no holes are just open). How did you figure out the right ratio of holes? Did you do any kind of special nozzles (e.g., brass inserts), or just holes in a steel tube frame?

Cheers,
Richard

[Otto Nobedder]

Richard,

The CFM requirements depend entirely on the smoothness of the mating surfaces. The volume of escaping air limits the PSI giving you lift. For two "perfect" surfaces, 1 PSI will lift 1 pound for each square inch of surface area.

In the plastic example, I used a router to cut a snowflake pattern from a central feed point to distribute compressed air to the far edges of a rectangular base, to distrubute air across the surface. Running 90 PSI over about 4 square feet (576 sq in) at available CFM (1/4" dia. orifice was the restricting point) can, in theory, lift 576 (sq in) * 90 pounds (per sq in), or almost 26 tons.

I had no need to get into Reynolds numbers and calculations, as the lift available FAR exceeded the weight I was working with.

Steve S

[Superiorwelding]

RichardH,
What did you decide for your welding surface?
I got ahold of a circle drop and I think I will give that 3 leg table a go. Will put it in the projects section....when I can get to it that is.
-Jonathan