On 1/2/2012 8:52 PM, ejrussell@mebtel.net wrote:
> Either my email isn't working or there haven't been any replies.
Me neither, but sometimes I don't see 100% of the posts. I always tend
to suspect I've messed up a setting on my end. :-)
> I think you need to apply some force to oppose the bend. Can the top
> be removed and flipped over? Or prop up the sagging ends and apply an
> opposing force to push the bow down. (hydraulic jack and a stout post
> against a garage door header?) If you try your idea of a clamping a
> beam along the top to pull the bow out you again need to over-pull it
> to take the bend out. Place a solid block in the middle then clamp
> down the ends to pull the bow out. Just laying it down on a flat
> floor and applying some heat won't do it. You need to bend it the
> other way almost as much as it is bent now to allow for spring back.
I can flip the whole table, but I thought after I got it straight, I'd
weld some supports to the table top to keep it flat. I can't imagine
there's ever any way I'll be able to bend it in the opposite direction
enough to keep it flat on its own.
> As for threaded holes for hold down jigs - I'd think threads in 1/2
> thick steel would be quite strong. You are wanting to simply hold
> things still - not bend heavy parts.
Just hold stuff still while welding, not bend them. Well, maybe 'bend'
them a fraction of an inch to true, but I think the tabletop itself will
usually be able to accomplish that. This is more that I used to be able
to stand on a two-foot wrench on a bolt on the old table and it wouldn't
even budge. I'd like to re-create something like that--massive overkill.
I want my great-grandkids' grandkids to be able to wop on one of those
hold-down bolts and have it not wiggle at all. We could use that table
as a surface plate and if anything was out a little, we'd crank it until
the parts mated, tack them, run a bead, and it was good. I probably
won't ever get *that* flat, but I can at least get the rest of it. I
don't want any of those holes stripping, ever. If I have to devote a
month to welding nuts on the underside of the table, so be it.
Alternatively, if anyone ever comes across a 4' x 4' hunk of 1.5"-thick
(or thicker) plate and you don't think you want it, give me a call.
> If you bolt your ground clamp to the top will that make your welder
> less portable? And does that matter to you? Or do you have an extra
> ground cable that would simply plug into the welder?
I will have an extra lead to devote solely to the table. And on the new
shop, I'm going to run that lead in a conduit through the slab so I
don't trip on it.
> No good ideas about paint. Obviously you can't paint the top and even
> the underside of the top might not hold paint for long if you are
> welding directly on it.
Yeah...I'm thinking the tabletop itself will have to be bare and I'll
just wipe it down a lot. I guess I'll see how far I can paint up the leg
before the paint starts to get destroyed by the heat. I'd imagine I
could go to the top--I probably won't be welding that near the center of
the table (where the leg attaches) anyway. On the other hand, 1/2" of
steel might carry away enough heat that the underside could take paint.
I don't know. And it's not like I'll be welding battleship armor on it,
even if I want the table to be built for it.
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