Plywood or MDF for a Jig

[cabinetman]

Yes. I can cite at least two specific cases.

Case #1. My old Grizzly H7827 drill press table that I bought of of LCHIEN. It came to me just fine, but within a year, the Melamine coated MDF swelled up like a balloon and was anything but flat. I particular it swelled around anywhere that had metal.

#2. Another example would be a jig I made a few years ago. Again melamine coated MDF. It was the infeed / outfeed tables I made for my Ryobi planer. They swole up within 6 months and made me tear the whole shebang apart and rethink my approach.

#3. My first Thien baffle was made of MDF. It lasted a year and a half before it swole up, again where metal contacted it.

are you sure you are using MDF with melamine ? I have never seen that. here is central texas, the only melamine I see is laminated onto particle board which really is crap.

robert

Good catch robert. Melamine has a substrate of particle board, which is an industrial board more dense than "chipboard" or "underlayment", not MDF.

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[BeauxTi]

went with the plywood - figured I had it on hand. It is partical board - I picked it up at a Habitat for Humanity restore. If you have not visted one - you may want to - esp if you need smaller stock - they have cabinet doors, moulding, misc board stock, etc - a lot of builders dump left-overs there. Just my $.02

[cabinetman]

went with the plywood - figured I had it on hand. It is partical board - I picked it up at a Habitat for Humanity restore. If you have not visted one - you may want to - esp if you need smaller stock - they have cabinet doors, moulding, misc board stock, etc - a lot of builders dump left-overs there. Just my $.02

We have a large HFH Restore here. There is usually a large selection of cabinet hardware, new, like full extension slides for $1 a set. Euro hinges & plates for 50 cents.

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[pelligrini]

Melamine has a substrate of particle board, which is an industrial board more dense than "chipboard" or "underlayment", not MDF.

Not all Melamine sheetgoods have a particleboard core. I picked up a sheet of MDF core 3/4" White Melamine a few years ago from Lowes. It was a really stupid idea for an outfeed table top, so I turned it into a drill press cart. http://www.bt3central.com/showpost.p...07&postcount=4

[chopnhack]

It was a really stupid idea for an outfeed table top, so I turned it into a drill press cart

Why? If the top was supported it wouldn't sag and the surface is nice and slick, what went wrong?

[pelligrini]

Why? If the top was supported it wouldn't sag and the surface is nice and slick, what went wrong?

It was a really stupid idea for a portable large outfeed table. My 21829 gets moved at the end of every day.

My stepson had helped me load and unload it in his truck when I bought it. When I went to break the 4x8 sheet down to size I was alone. I ended up taking my sawboard and sawhorses to it rather than move it to my shop. It still didn't dawn on me how impractical the 3/4 MDF was for portability when I was breaking it down. I finally called myself an idiot when I was trying to manhandle half the sheet to my shop. Even 1/2 size it was extremely heavy.

This worked much better than 3/4" MDF core Melamine: http://www.bt3central.com/showthread.php?t=41179

[LCHIEN]

"went with the plywood - figured I had it on hand. It is partical board"

which was it, particle board or plywood? Two very different materials. Gotta be one or the other.

[All Thumbs]

"went with the plywood - figured I had it on hand. It is partical board"

which was it, particle board or plywood? Two very different materials. Gotta be one or the other.

Actually, it could be hardboard (Masonite).

[chopnhack]

Gotcha Erik. Portable indeed.. At least that hollow core door assembly fits the bill better.

[BeauxTi]

sorry - sometimes too frugal with words -- what I meant - I went with the plywood for sacrificial material and yes the melamine was particle board not MDF