Torsion box application - suggestions welcome

[Prometheus]

Hello all,

We recently moved around the house a bit, and found that we have enough room in what used to be the living room to install a smallish pool table (it's a big room- too big to be comfortable when watching tv)

I checked around, and those suckers are expensive! So, I looked at just getting the slate- but it seems that's where all the cost is... and it is still outside my price range right now.

My wife suggested one of those cheap little ones they sell at various retailers from time to time, but I hate to throw away money on junk made from termite puke and plastic veneer. They're too small, and as an added bonus, ugly.

So here's my plan- and I'd welcome any advice or experiences you may have had with parts or all of this.

I'm thinking a torsion box may be the thing for the table. My budget will accomodate a top made of MDF and formica, but not stone. I've got a working idea that I could make the torsion box with two or three

4' x 8' sheets of 3/4" MDF by cutting two 3' x 6' sheets for the top and bottom, and making the internal ribs from the leftovers. It'd make a small table, but I want to be able to use it, not look at it! :)

Because MDF is a little on the soft side, I'm thinking it couldn't hurt to screw the top and bottom to the ribs, fill the screw heads with bondo, sand flat, and then laminate the top to make it a little less prone to dents and dings.

Here are the main points of consideration as I see them:

1. Will 3/4" MDF that has been laminated be tough enough to withstand the odd billiard ball dropped on it, or is it going to look like the surface of the moon in a few months?

1. With the torsion box design, is it necessary to laminate both sides to equalize moisture content changes, or does the lattice inside eliminate that as a concern?

2. Would it add structural strength (beyond simple ballast) to fill the cavities between the ribs with some material (foam board, sand, concrete, whatever you fancy for something like this...) or is that an unnecessary step? To make the table heavy, I can always weigh down the legs.

General torsion box advice/experiences welcomed here- I know a lot of you guys use them as assembly tables, and I figure those must get a bit of abuse as well.

Lest anyone get too worked up about the basic premise- I fully understand that this won't make for a professional table, but I'm not a pool shark, so I figure it'll be good enough for screwing around in the rec room. It's got to be better than a $200 plastic thing, anyhow. I just want to avoid any particularly stupid mistakes when figuring out the general plan for the top.

Also, I have specified MDF as opposed to plywood because it is a waste to use funiture grade hardwood ply and then cover it with felt, and the general softwood stuff is too irregular for me to trust it in this application.

[boorite]

How about a bed made of Slatron, which is like particle board but 20x denser and made especially for pool tables? Players regard anything not-slate as a toy, but I think Slatron is as close as you can get. Anything else is not going to be flat or stable enough. Even commercial Slatron tables are only warranteed for 7 years.

There's something else called Permaslate, but it's harder to find info on.

[Prometheus]

Thanks for the suggestion- I'm going to run a search on it now. Maybe there's a way to integrate the two (Slatron and a torsion box, that is) and get more than 7 yrs out of it.

[Prometheus]

Well... I did check on the stuff, but it kind of looks like it it is almost as expensive as a slate kit. As you seem to have some knowledge of the process and construction, have you ever run across a torsion box system for a pool table? I've been doing some searching, and it would appear that this hasn't been done, at least commercially.

While the Slatron thing is sort of interesting, I can see why they have a limited warranty- even if you've got mdf a million inches thick compressed to an inch, it'll still be mdf, and prone to warp in humidity. Seems like a little engineering ala the torsion box could go a long way in this application.

On the bright side, the forums I encountered that mentioned Slatron also mentioned MDF, so it must be at least marginally suitable for the application- at least for a non-expert like myself.

[Robatoy]

I think a torsion box would work well. I would start with 3/4 HDF

has double the impact resistance over MDF and would make a wonderful substrate for laminate. Whenever you laminate anything, and flatness is important, always use a balance sheet on the other side, even if it is a torsion box. (DON'T ask!) The next trick is to get your adhesive onto the laminate and substrate without a variance in thickness. One word: spray. Those cans of 3M work really well... a bit pricy.

It is difficult to make a uniform sandwich. I would never screw into the lattice/matrix, unless you made it from hardwood. MDF/HDF simply will not hold a screw in the endgrain. I wouldn't use screws at all. Make sure the bottom sheet is supported on a flat surface. Trace the outlines of your lattice. Pour a copious amount of white PVA within the traces, put the lattice down and pour lots of white, thick PVA glue on the top of the lattice edges and lay down the top sheet. Let it find its own level and then weigh down with enough bags of topsoil to completely cover the project. A big vacuum bag would be ideal... but who has one, eh? Topsoil is useful for all kinds of gardening adventures. Sandbags are better, but what do you do with all that sand afterwards? Do not touch for 48 hours. Castle the top and bottom edges of the lattice by cutting saw-blade grooves, 1/8 deep, across the strips on 1-1/2" intervals to balance air pressure build-up between the compartments. Make sure the air can escape to the outside of the box.

r

[CW]

[John]

Would a kitchen cabinet top perhaps be cheaper and easier to obtain and be more likely to stay flat? If you can't afford slate, might Corian be within your reach? If so then it'll probably be good enough for the rec room and might last you much more than a couple of years.

J.

[CW]

[Lew Hodgett]

Prometheus wrote: > Hello all, >

Take a look at a bumper pool table with a removable top to make it a std table.

At one time in my life, was a very serious pool/billiards/snooker player.

I found trying to play on anything other than a full sized regulation table very frustrating; however, bumper pool was a lot of fun.

Lew

[Art Greenberg]

Why?

[Robatoy]

Because you are building a pool table, not a barometer?

[J T]

Fri, Sep 22, 2006, 8:01pm (EDT-1) [e-mail] (Prometheus) doth confusedly posteth: We recently moved around the house a bit, and found that we have enough room in what used to be the living room to install a smallish pool table (it's a big room- too big to be comfortable when watching tv)

Are yyou saying you moved your persons around your house? Or that you move the house itself?

The one thing in life that I think I'm actually envious of other people about is that I don't have room for a pool table. But if I did, the only type I would want is one of the older tables, the type used in real pool halls when I was a kid. You can actually buy one that'd been professionally refurbished for a pretty reasonable price. Last time I checked around $1,000-1,500, and usually includes setup in your home, which I consider a pretty decent price. What I would consider gravy would be a room with one of those old pool tables, AND an old refurbished snooker table, pool chairs, the wires with the score markers, a pill pool bottle, the whole nine yards. Children would NOT allowed to play, no drinks on the tables, no masse shote, etc., in other words, all the old pool hall rules. And GREEN felt, none of the tan, blue, or other sissy colors; pool tables are meant to have green felt. Ah, brings back memories of a well spent youth.

I dunno about any of what you've asked, but do know theres plans on-line, both pay and free.

JOAT You'll never get anywhere if you believe what you "hear". What do you "know"?.

- Granny Weatherwax

[J T]

Sat, Sep 23, 2006, 5:17pm (EDT+4) [e-mail] (Lew=A0Hodgett) doth sayeth: bumper pool was a lot of fun.

Yeah, it was, my old man got one when I was a kid. But after awhile I got good enough to pretty much sink each ball with one shot. Wasn't quite as much fun after that.

JOAT You'll never get anywhere if you believe what you "hear". What do you "know"?.

- Granny Weatherwax

[Art Greenberg]

Whatever. I have a 4 x 8 work table I built as a torsion box without doing this. Simply didn't even think about it, and had never seen the suggestion. I suppose it would be interesting to actually try to measure deflection of the skins with changes in barometric pressure.

[Prometheus]

Well, I'll work the numbers for you. First off, I have all the tools already, so I'm not going to count them in.

Materials:

$900 -- slate or $75 mdf torsion box $300 (give or take) pockets & bumpers

So there we're at $375- I can put another $200-500 into that, and build the legs and rails out of solid hardwood (probably birch, but I haven't decided)

I'm not going to count the time, because it's for me and I'll enjoy the project.

So, it'll run at a rough estimate around $1100 (figuring tax, balls, felt, cues, unexpected hardware, etc)

While this doesn't seem like much of a savings, you have to figure in shipping and setup fees, which would run close to $400, and the fact that a $1200 slate table is almost always made with a cheap and unattractive laminated MDF rail system and legs. It is also going to be next to impossible to move if I sell my house or just want to change it's location. A lighter torsion box table would have the benefit of being able to move it coupled with a much more pleasing base should I decide to change it into a dining room table at some point in the future.

So, given that, I'd say it'll save me at least a couple grand and fit my needs more precisely than a manufactured unit. Even setting aside the price tags, it is still a savings in that the value of it will be greater to me than something that looks like it came from the local pub.

Don't mean to snipe at you, I just really do see a real savings in making my own stuff- the trick is to compare apples to apples, and in this case, I feel I can get a table that looks like it cost $5000 for the cost of one that looks like I got it at a yard sale. As far as the table goes, if it works at all, it's good enough- I'm not a pool shark, I just like goofing around with it. If the MDF goes south in 5 or 10 years, I can always replace it- and it will be cheaper than fixing a cracked slate!

[Prometheus]

I guess the concern I have with the cabinet top is that the ones I've seen were made of particle board, and do not have the extra support of the internal ribs.

Corian is something I'll have to look into, but IIRC, I could just get slate or granite for that price. I've put some thought into getting granite measuring tops one at a time and setting them as well, but that has it's own problems, mainly in drilling and cutting the pocket reliefs.

[Prometheus]

I'll definately see if I can find that locally.

It's also quite doable to use a cup gun for laminate adhesive, and I just happen to have one. :)

Even better, really. That way there's nothing to fill in.

All good suggestions- thanks!

[Prometheus]

That was the wife's idea, and we were going to go look at those tomorrow. Good to hear another vote in favor of that- I've never played bumper pool, so I was a little leery of the idea.

[Prometheus]

To clarify: We moved the furniture from the living room into the office and moved the computers into the living room. They only take up about 3 feet of one end, so now we have a huge virtually empty room.

That's one of the options as well, just not on topic for the wreck. A lot of bars open and close in these parts, and used tables can be gotten if a guy looks around enough.

Well, that's sort of the idea, only with the PCs on one end of the room, and only one table. I'm on the lookout for a good dartboard and the hanging green light as well.

Checked out the plans, but I'll probably wing it for everything but the bumper heights and pocket sizes if I do build it. I gave up other peoples' plans a couple of years ago- they work fine, but it's not as fun in the end.

[CW]

I just priced a table. Made of maple, full size 8 foot slate top, free shipping, free installation, American made. $2614.00.

details on their site.