[TheForge] Welding Platen Question

[David E. Smucker]

I just recently bought a used welding platen.  I have no idea how old it is 
or it's history.  It is 48" by 60" inches with 1-1/2 square holes.  I was 
told it at one time was used in a gulf coast ship yard.  Best I can tell it 
has never be reground.

What is strange to me is that it has a uniform crown of about .060 inches in 
both directions.  This is based on a somewhat quick check with a good (not 
perfect) 5 foot straight edge.  (And yes I turned the straight edge over and 
checked using both sides.)

I would not be surprised in a old welding platen to find dips or other "non 
flat" areas but am surprised to find a quite uniform crown.  It would seem 
that it was machined in at time of original manufacture.

Any one ever hear of this?

I have seen crown put into items that are going to be under very heavy load 
so that the will be "flat" when loaded but not in a welding platen that is 3 
inches thick over most of the surface and 6 inches at the edges and a center 
support rib.

I can improve a lot on this by hand grinding and checking and hand grinding 
and checking etc.  I am too far back in the woods and too cheap to send it 
somewhere to be blancher ground -- weight without the stand is about 2100 
pounds.

Dave Smucker