Locate Bolts under spoilboard?

[mjindustry]

Needing to remove my glued down spoil-board. Can I locate the underlying bolt locations for boring out with the router? Thought maybe someone would have a way of doing this, as I'd rather do that than plain it down.

Thank you

[myxpykalix]

My plywood plenum is bolted directly to the table and on top of the plenum the spoilboard is glued. Mine is a custom table so i'm not sure about yours but don't your bolts go thru the table and bolt underneath?

If so then just look underneath, if not then maybe you could get some of those "rare earth" magnets that are real strong (I bought some at BigLots for a couple bucks) and move them across the table till you attract the bolts then mark it.

If you are afraid that by thinning down your spoilboard that you are going to hit those bolts then I would use the magnets to find the location then use a "plug cutter bit" to cut out where the head is and replace the metal bits with nylon nuts and bolts (the kind you use to hold your toilet lid on with).

[mjindustry]

Thanks Jack! You're always such a big help, good thing too with guys like me around.

We're moving to a new shop, currently in my basement. I have to completely tear down my prt 96 to get it up stairs. Never occurred to me until just now...get ready for it...wait for it... remove nuts, lift board! :rolleyes:

Seriously, am I right though?

[myxpykalix]

Again since i'm not familiar with your model table it would seem that the simple thing to do even if the plenum and spoilboard are glued together would be to just remove all nuts and lift. Then reverse that when you replace however I can see where when you are trying to retighten the bolt may want to just spin with no way to hold it to tighten.

What you could do to minimize destruction to spoilboard would be to take a icepick or scredriver and pound it down till you find the edge of the bolt. Once you find the edge and have the screwdriver pounded down next to it so the head won't turn you can then go under and tighten the nuts then get you some fine sawdust and glue mixed and put in the hole then you're back in business.

It has been 4 years since i put mine down so i don't recall whether or not in the original design of the plenum I used if the plan called for a countersink hole where each nut went.
I am almost 100% sure that my bolts were countersunk into the plywood so that even if you have to skin the whole spoilboard down to the plenum you won't hit metal. (I could be wrong!)

[dray]

I use a Neodymium magnet to locate bolts. Simple and effective.