Experience is the best teacher

Hi Everyone,

Experience is the Best Teacher---Or to put it another way---I screwed up!

Experience is the Best Teacher---But the lessons are so darned expensive.

Anyway, by now you have figured out that I got myself into another mess. Picture this---a 27 x 72 inch piece of ¾ Apple plywood. Glued to this are two more pieces of ¾ plywood making one piece 27 x72 x a little over two inches thick. This was glued with Tite Bond slow drying glue (which seems to dry just as fast as the regular kind). Glenn and I both worked applying glue, to glue the smaller pieces to the large one, one section at a time.

A couple days later, all by myself, I apply the same glue to add another 27 x 72 inch layer of ply. This was all one piece. Glue applied with a roller (Soft rubber wallpaper roller. Glue came right off of it when I was through). Glue went on rapidly; I thought. However, it was becoming difficult to remove the roller from the plywood near the end.

I immediately ran woodscrews thru the top layer of ply into the second layer. The screws just spun around without appearing to hold anything. Being a newbie, I had selected the wrong kind of screws. So I immediately began piling on weight. Weight was in the form of 16 pound slabs of cement. I forget the exact count but it was over 25 of them (see photo).

Everything was great UNTIL a day and a half later when I removed the weights. I had nothin’ stuck to nuttin’ in several areas that I ccould see. One area is 36 inches by, up to 12 inches in from the edge with a 3/32 inch gap. When I close the gap with a clamp the ripples in the bottom of the bench top (yes this was to be a bench top). The riples are very visible with the naked eye. I have no idea what percentage of the total job is actually glued. I just know that there are some major non-sticking areas.

QUESTION: What do I do now?
...Trash it and spend another couple hundred dollars for more plywood?
...Try to separate the two panels? I assume there would be, at least, some tear-out. Perhaps with some judicial planning and use of filler, I would lose only one sheet of plywood instead of three. If this is the choice, how would I do it?
...Is there a way to separate them? Tite Bond says that there is NO solvent for the glue. The man also said, “Heat from a heat gun, if applied soon enough, might loosen the remaining glue.” That is one heck of a heat sink. I think that trying to heat a laminate of three pieces of ¾ inch 27 x72 plywood enough to soften the glue is a good prescription for a burned down workshop.

I WILL BE REALLY GLAD when I have enough experience to keep myself out of most problems.

All help will be greatly appreciated.

Enjoy,

Jim

I have tried to add a link to the photo. I don't know if it attached or not.
 
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Jim, I suspect some people will disagree with me, but if you turn the piece over so that the "rippled" side is the bottom of the benchtop, I don't see that it'll make a whole lot of difference in the use of the bench. You still have the mass; it's just not perfectly flat on the bottom. I don't think the performance of the bench will be affected enough to warrant replacing the top. (I think pulling the layers apart would be an workable mess.)

If you end up finding voids along the edge or in places where you cut into the top (such as recesses for a vise), just squirt 'em full of epoxy and call it good.

And you might want to put a cold pack on the spot on your forehead. Beating your head on the wall sure can leave a mark. :bang: :D We've all had our moments like that in the shop.
 
I WILL BE REALLY GLAD when I have enough experience to keep myself out of most problems.

Jim, as long as we work in our shops and keep learning new things, this type of learning experience can and will happen. Instead of raising your blood pressure, be happy this learning experience happened with your workbench instead of a laminating job that went on the lathe :eek: :eek: :doh:!

I assume you wanted the apple plywood on the top of the bench so going one step further from Vaughn's solution, turn the mess over, take the lessons learned and apply apple ply to the other side making it your top then when fastening the top to the legs and frame and fastening all components to the table, pulling it all together. Could even utilize some bench dog holes and put some carriage bolts in the holes to hold it together in the center. :dunno:
Now go out to your shop and make some lemonade out of this lemon! :D
Good luck Jim.
 
I agree with Vaughn's suggestion, however if you really want to try to separate them due to the fact that some areas are not glued and this will help try this system that I used once and it worked pretty well.

Tie strongly a thick rod of about one inch diameter by 15 - 20 inches long to each end of a very thin piano wire somewhat longer than the width of the panel.

Find an unglued corner where you can slide in the wire, if not pry one open enough with a screwdriver so that you can slide in the wire by its center aproximately.

Then get a fellow's help and by pulling each one of you from the rods as if it was a two man saw pull the wire towards the other end of the board moving it back and forth as if you were sawing.

Obviuously the board has to be secured to a bench or something heavy.

You can help the process by inserting thin wedges on the areas already freed,
beware! do no make those wedges too high or you risk splitting the board.

It is better put them in and wait, push them further and wait, let the tension build on the glue and creep it.

I hope I've explained myself well, if not let me know.
 
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