Gluing MDF together for a ping pong top?

[Rob Will]

I want to glue two 5'x9' sheets of 3/4" MDF together to make a heavy-duty ping pong table.

Yes, that is probably overkill but it is going to be used by teenage boys in an unheated building. I want to ensure that the top stays together, stays flat and has a strong ball bounce. Besides, the MDF is really cheap.

What glue can I use to laminate two sheets of 3/4" MDF together?
I want something that dries hard and does not cause the MDF to swell.

I will probably use some 1-1/4" screws from the bottom side to hold the two sheets together for gluing.

The finished top will probably be attached to a 2x6 frame with pocket screws.

Rob

[Mike Armstrong]

. . .to make a heavy-duty ping pong table.
With the emphasis on heavy! What's that top gonna weigh, 200lbs + ?

It's certainly not a cheaper, easier alternative, but have you ever considered a torsion box?

Mike

[Robert Payne]

I'd use contact cement on each surface and get some help to put the two sheets together using some long dowels after the cement had tacked up. As you may know, alignment is critical before the glue surfaces touch because they'll never come apart once they touch.

[Roger Savatteri]

Rob,

I've found using Unibond 800 from Vacupress to work very well gluing MDF together, I also use it for bonding other "wood" materials as well. http://www.vacupress.com/veneerglue.htm
It has (in Southern Calif) at least a half hour working time. I measure out the resin/catalyst ratio by weight. It's a urea resin & comes in plastic gallon containers in a liquid form with a powdered catalyst. If you order it, keep in mind that they have the catalyst in about 3 different colors. (to better match the wood you are working with. Although it would not really make a difference for your ping pong table, you might consider the other woods you work with when deciding which catalyst color to order. (for the leftover) It's great for veneers, and though I usually use a vacuum table, one could also use clamps and cauls to facilitate your bond.

hope this helps,
Roger

[Cliff Rohrabacher]

http://www.woodcentral.com/bparticles/mdf_faq.shtml

http://www.talkshopbot.com/forum/messages/312/17117.html?1167698063

http://www.woodweb.com/knowledge_base/Glue_for_MDF_Mouldings.html

[Tom Esh]

Plain old PVA (Titebond) works very well. I've done a number of shop tables and fixtures with it using only gravity as a clamp. Going on 5 yrs for the oldest now with no signs of de-lamination. I generally use dowels in each corner to maintain alignment during glue up. Be sure to seal the whole thing adequately (including edges if you won't be gluing trim or banding to them) to prevent uneven moisture penetration from causing it to warp. I use at least two applications of shellac before any other finish. Bare MDF is thirsty stuff and shellac is a fast and cheap way to quench it before applying any slower and costlier top coats. A piece that size might drink most of a quart.

[Brad Townsend]

Rob,

If its going to be used by teenagers, you are probably in the wrong forum. You should find a metal fabrication forum and build one from steel plate.:D

Seriously, as one who plays the game frequently, I have some concerns about MDF for a ping pong table. The edges of the table would be particularly vulnerable. Might want to try taking a small piece of MDF and beating on it with the edge of a paddle and see if you can dent it.

[Lee Koepke]

the other concern would be support for the piece, MDF is not structurally stable in span condition. maybe one layer of plywood, one layer of mdf ??

[Rob Will]

Rob,

If its going to be used by teenagers, you are probably in the wrong forum. You should find a metal fabrication forum and build one from steel plate.:D

Seriously, as one who plays the game frequently, I have some concerns about MDF for a ping pong table. The edges of the table would be particularly vulnerable. Might want to try taking a small piece of MDF and beating on it with the edge of a paddle and see if you can dent it.

Good point Brad, do you think I should band the edges with a hardwood strip?

dowells, dominos, finish nails?

This is not a highly finished project but it needs to be durable. It is going in an old (unheated) shop on my neighbor's farm. As far as I know, the MDF is the only local material that I can buy that is large enough to make the top. I'll keep looking though.

Rob

[Rob Will]

Thanks Roger, I ordered some Unibond 800.

[Rob Will]

Now that's a thought. The bottom (plywood) would not have to be one piece. I could build the beast upside down on the floor, laminating plywood strips to the MDF.
Let the plywood run a little wild then use my spiral pattern bit to trim everything to the the exact size of the MDF. If I need a more durable top edge I could rabbet in a 1/2" x 3/8" strip of some sort of hardwood.(?)

Rob

[Howard Acheson]

Solvent based contact cement is the best way to laminate MDF together.

However, I would recommend against it. The table is going to be really heavy and the edge is going to be very subject to chipping and not very durable. At the very least, you will have to band the edges with hardwood. Second, MDF is not a very stiff material and, unless you adequately support it from underneath, it's going to sag.

Personally, I would use a plywood with an appropriate frame underneath (sort of the torsion box already suggested).

[Brad Townsend]

Good point Brad, do you think I should band the edges with a hardwood strip?

dowells, dominos, finish nails?

This is not a highly finished project but it needs to be durable. It is going in an old (unheated) shop on my neighbor's farm. As far as I know, the MDF is the only local material that I can buy that is large enough to make the top. I'll keep looking though.

Rob
Yeah, the size is a real issue. That is unless you buy twice as much sheet material, use a full sheet for each side with a break under the net, and have a lot of waste left over. Then it gets kind of pricey.

A friend of mine bought a really nice ping pong table top at a large sporting goods store. It's designed to go on top of a pool table. Think he paid around a hundred for it. By the time you buy, haul, cut up and finish MDF, ply or whatever, you might be money ahead to just buy a top ready made. You could still make a base for it.

[Rob Will]

My customer has decided that she would rather have the ping pong table constructed in two separate pieces. That means that I can use 5'x5' Baltic Birch instead of the MDF. Are you guys more comfortable with the Birch ply?

Thanks,
Rob

[Tom Esh]

My customer has decided that she would rather have the ping pong table constructed in two separate pieces. That means that I can use 5'x5' Baltic Birch instead of the MDF. Are you guys more comfortable with the Birch ply?

MDF will play better, or faster at least. The same properties that make it ideal for speaker enclosures will give the ball more bounce than plywood can. Actually a single 3/4 inch layer would be adequate for that purpose. Thicker would help resist sagging, but with MDF you'd want plenty of support under it in any case.

[Eric Gustafson]

MDF will play better, or faster at least. The same properties that make it ideal for speaker enclosures will give the ball more bounce than plywood can. Actually a single 3/4 inch layer would be adequate for that purpose. Thicker would help resist sagging, but with MDF you'd want plenty of support under it in any case.

Where can you buy MDF big enough to make a ping pong table?

[Rob Will]

Where can you buy MDF big enough to make a ping pong table?

Nashville Plywood carries a 3/4" MDF that is 60" x 108".
$36.00 a sheet. They also have a satellite store in Hopkinsville, KY.

Rob

[Lee Koepke]

My customer has decided that she would rather have the ping pong table constructed in two separate pieces. That means that I can use 5'x5' Baltic Birch instead of the MDF. Are you guys more comfortable with the Birch ply?

Thanks,
Rob
you still can use one layer mdf for top surface and ply below for stability. would like to see pictures when you get done ..

[Rob Will]

you still can use one layer mdf for top surface and ply below for stability. would like to see pictures when you get done ..

We are on the same page Lee.
After making several dead-end inquiries, I found a pool table conversion top at Sears for $90 :D. I ordered it online and it is being shipped to my local Sears store in about 5 days. This is going to save me a ton of time and money by not having to fabricate and paint the top (thanks Brad). In addition, the hard and dense particle board my be the best playing surface (thanks Tom).

The 1/2" particle board top comes in two pieces.

Now for the extra strong part........
I'm going to use the Unibond 800 (thanks Roger) to laminate the finished particle board to 3/4" baltic birch (thanks Lee). The resulting 1-1/4" ping pong top will be attached to a 2x lumber frame with pocket screws.

Any suggestions about what type of lumber would be most stable for the frame? I might be able to lay my hands on some #1 grade fir at a local yard. We could ensure a perfect edge by running the top edge over the jointer.

As far as the lamination goes, can I rough up the back side of the particle board and use the Unibond 800 to glue it directly to the baltic birch? If I use a couple of short screws to keep the parts in position, can I use evenly placed weight instead of clamping cauls?

Rob

[jack duren]

Particle board is more stable than MDF...

[Roger Savatteri]

As far as the lamination goes, can I rough up the back side of the particle board and use the Unibond 800 to glue it directly to the baltic birch? If I use a couple of short screws to keep the parts in position, can I use evenly placed weight instead of clamping cauls?
Rob

hello again Rob,
Roughing up the two gluing surfaces with 80 grit is a good idea. In spreading out the Unibond 800, I would recommend using a foam roller cover and spreading out a uniform coating on both surfaces. Since this is your first time using this adhesive I would suggest you do a run through with some large scrap (1' by 2' at least) to get a feel for it. Give it a day, then do the real thing. You could wash your foam roller with cold water only (warm water will accelerate the glue) between uses. I usually get 2 uses from a foam sleeve, maybe three. The best foam sleeves to use are the thin black ones mounted on a cardboard sleeve that fits over a standard size roller (not the squishy foam frank-footer size ones)

hmm, If you don't want to use clamping cauls, I would round up all your clamps and then clamp your edges and then put heavy weights towards the center. Unibond likes lots of pressure. Normally, I would oversize my cuts and trim down after it's cured. Since your using a prefab top, may I suggest screwing down two blocks to your work table a couple of inches high on the two corner sides (four blocks) That way after gluing up the surfaces you would lock in one then flip the other over & lock it on top of the first. Presto, tight fit around the edges. Caution, put blue painters tape on the edges of the blocks that are going to rub up against the combined edges. Also, get yourself a roll of wax paper and lay it on the surface of your worktable or anywhere that the squeeze out may drip over. Have a wet/damp rag ready to wipe up the squeeze out. After this whole exercise is over I would keep the leftover gallon of Unibond in the fridge - if your in a warm climate. By running through this will a sample glue up, you will prevent any hiccups when doing the table.

P.s. mix the glue/ catalyst very well & if your unsure of the quantities needed, mix one lot and have another lot pre measured ready to go once gluing commences.

P.s. 2 .....since your placing the top surface face down, applying blue tape all around the surface edge would be a good idea. You wouldn't want any of that squeeze out running over onto the surface. You shouldn't have that much if you apply it properly. Remember, practice first.

all the best, Roger

[Rob Will]

Thanks for the details Roger.
That was a lot of work and I really appreciate it.

Rob

[Brad Townsend]

Hello again Rob,

Think you made a good choice buying the top. Once laminated to the BB, it should withstand about anything.

This is the frame I made for my table. It's just 2x4s and 4x4s. I jointed and thickness planed all of them first to get everything uniform, then cut all the dados on my tablesaw. Assembled everything with 1/4" carriage bolts and took a router and roundover bit to all the edges. It's rock solid and didn't cost a fortune to make.

Brad

http://img.photobucket.com/albums/v238/btownsend/DSCN1848.jpg

[Rob Will]

Hello again Rob,
Think you made a good choice buying the top. Once laminated to the BB, it should withstand about anything.
This is the frame I made for my table. It's just 2x4s and 4x4s. I jointed and thickness planed all of them first to get everything uniform, then cut all the dados on my tablesaw. Assembled everything with 1/4" carriage bolts and took a router and roundover bit to all the edges. It's rock solid and didn't cost a fortune to make.Brad

Thanks Brad, that is one nice table you put together. Hopefully I can find some 2x4's that nice to put this one together.

Our table goes in an old farm shop where there is a large sliding door - so we might use glue and 3" screws to put ours together. We probably won't make our's as nice as yours but I have printed the picture you posted to use as a guide.

Rob