I have a Delta contractor's saw that I bought back in the mid 80's, which is a pretty heavy duty saw. I had it in storage for about 4 years, and in the last year I put it back to work in my shop, primarily used for dados. I kept having trouble getting the depths of my dadoes consistent, and attributed it to warped panels.
Last night I put a straight edge on the cast iron top, and to my surprise it is crowned up in the middle 1/16"! I tried two other straight edges, and they all read the same. I don't remember this saw having a crown in it like this, and I don't know if it could have happened somehow in storage, but it is a problem.
Is there any way to get this crown out? I imagine that if it was brought to a machine shop, somehow they could resurface it flat, I just don't know that it is worth the cost or the time for this. I was possibly planning to remove the saw from the shop to save space, but I also wouldn't mind keeping it for dados if it were flat.
From contributor S:
I had the exact same problem. Saw was great when new, and then one day about 10 years later I was checking something or other and noticed the hump. I also had a dish towards one side. I phoned the local Delta repair location, and talked to the tech (he was an old hand, very knowledgeable). He said because cast was so malleable, it could be "tuned" - essentially banged flat after supporting on a flat wood surface. This required a pretty experienced hand, though. Didn't get to this however, because they gave me a new top. Pretty amazing considering the saw was 10 years or more old, and well out of warranty.