Perpendicular joinery

[PDQ]

All the ones I put up had nuts, bolts and washers to hold the 2X4's = together.

--=20

PDQ

-- =20 "Martin" wrote in message = news:TkrYd.17430$ [e-mail]... | What's the best hardware to use when join two pieces of plywood or MDF = (say,=20 | 3/4 inch thick) at 90 degrees for repeated assembly-disassembly? |=20 | The context of this is that I'm trying to design various pieces of = furniture=20 | for a tradeshow booth. Everything needs to be torn down to flat = pieces for=20 | crating and shipping. The pieces must also survive repeated=20 | assemble-disassemble cycles (to be good for more than one show). |=20 | I'm having a local carpenter do the work, but he's used to building = pieces=20 | that are assembled once and left alone for many years. I'm trying to = help=20 | figure out how to make it easy to assemble and tear-down the pieces to = be=20 | built. |=20 | One approach that's common on assemble-it-yourself furniture is a bolt = with=20 | the little cylindrical nut. This works, but a certain degree of = precision=20 | is required in fabrication. May not be too bad if you make a jig. |=20 | I wonder if there's a clever L bracket type approach that can be = surface=20 | mounted and provide a strong joint that can be assembled and taken = down=20 | quickly. |=20 | I'd greatly appreciate any links or ideas you may be able to offer. |=20 | Thanks, |=20 | -Martin |=20 |

[Martin]

What's the best hardware to use when join two pieces of plywood or MDF (say,

3/4 inch thick) at 90 degrees for repeated assembly-disassembly?

The context of this is that I'm trying to design various pieces of furniture for a tradeshow booth. Everything needs to be torn down to flat pieces for crating and shipping. The pieces must also survive repeated assemble-disassemble cycles (to be good for more than one show).

I'm having a local carpenter do the work, but he's used to building pieces that are assembled once and left alone for many years. I'm trying to help figure out how to make it easy to assemble and tear-down the pieces to be built.

One approach that's common on assemble-it-yourself furniture is a bolt with the little cylindrical nut. This works, but a certain degree of precision is required in fabrication. May not be too bad if you make a jig.

I wonder if there's a clever L bracket type approach that can be surface mounted and provide a strong joint that can be assembled and taken down quickly.

I'd greatly appreciate any links or ideas you may be able to offer.

Thanks,

-Martin

[Mike Marlow]

For knock down stuff like you're talking about, I wouldn't use MDF. The stuff is termite puke with unknown substances holding it all together. It's heavy - and that will not work well for this application, and it is not durable stuff. The operative word in "knock down" is "knock". MDF does not stand up to knocks.

3/4" might be too heavy, no matter what the chosen material. That's a lot of weight and bulk. Look at the commercial stuff and see what they use. The commercial stuff holds up to use and shipping very well.

Not that much precision. Any carpenter should be able to achieve that degree of precision with no difficulty.

Sure - L brackets would work and they are commonly available at hardware stores. More work to put together and tear down, but they'd work. I'd try to avoid anything that requires screws going into the wood. The holes just won't stand up to repeated assembly and disassembly. That's what makes the cam lock nuts or the likes a better solution. You're going into metal with a bolt instead of wood with a screw. Take a look at what the commercial products use. You'll be able to find the same kind of fasteners they use somewhere on the net.

Good luck,

[Martin]

Sorry, I wasn't very clear. By "clever L bracket" I meant some sort of a split L bracket. Each half would be permanently affixed to the corresponding piece of wood and the mating/unmating would simply be metal-to-metal, no need to repeatedly deal with screws going into wood.

One interesting idea I got while browsing the Rockler catalog was to use bed-rail brackets. I may get one and see what they look like. I am tring to keep the various pieces as flat as possible for crating/shippping purposes. So far it seems that the bolt+cylindrical nut may be the best approach.

Thanks,

-Martin

[Mike Marlow]

No - you said it well enough. I just missed it. I have to bet an internet search would turn up something.

Bed rails may work - they lack rigidity in the structure, but by the time you tie it all together, it may be rigid enough. Think I'd rather do the clever L bracket idea though.

[Rick Cook]

Loose-pin hinges, possibly with stop blocks to keep the angle between the pieces correct.

One very important point. Make sure the pieces are small enough to be easily handled by one person.

--RC

[Rick Cook]

If you want something like bed rails, get some Gorilla shelving. Very sturdy, easy to assemble in just about any shape and not too expensive.

--RC

[mare]

The IMHO nicest way: Lamello Invis

Not cheap however...

Other knock down harware suitable for MDF are metal biscuits

and these Knock-Down Fittings more or less the same as IKEA uses on it's kitchens.

If you need to assemble and disassemble I would use plywood instead of MDF. MDF is heavy and chips easily during transport.

[Jeff]

There are specific metal fasteners made to do exactly what you want to. I have seen then in several catalogs, but I can't tell you specifically which ones. Look in Rockler and Woodcraft to start. Or the internet search for knockdown fasteners would be a good idea too.

Good Luck.

Jeff

[Edwin Pawlowski]

Having set up and taken down a few tradeshow booths, the last material I'd use is MDF. Too heavy to handle and it chips too easily for the repeated use. Plywood is my choice. You will also be paying more for shipping cost to each show.

If you were to use 1/2" material, the #3070 would be a good choice. Maybe there is a 3/4" available elsewhere.

[Morris Dovey]

Martin...

Here are two (possibly) useful resource pages:

[Robatoy]

[snipperectomy]

Aluminum tubing and stretched canvas. No MDF...too heavy and easily damaged as many Wreckers have stated. If flat surfaces with rigidity are a must, gator boards make for nice displays. Foam-core with taped edges looks nice. Aluminum honeycomb, nicer yet, but expensive.

I do not know where those displays are going, but my experience has been that 'your' spot is always the opposite side of the building away from the parking lot/loading dock.

[Robert Bonomi]

Authoritative answer: "It depends".

"Size matters" A *LOT*.

How _big_ a space you have, how big the 'furniture' needs to be, how *small* it has to disassemble to.

what kind of _weight_ you can tolerate -- which correlates directly to shipping costs.

Unless you've got some *really* exotic needs, or are only going to be using at shows where you (the company) do the actual transport *yourselves* i.e. *your* vehicle, not sending by a shipping company. you are a *LOT* better off looking at some of the stuff that is *made* for the purpose.

The savings in shipping charges, due to advanced technology materials and construction, can pay for the 'high priced stuff' *amazingly* quickly. I mean like 5 or 6 shows, if they're several hundred miles away from 'home'.

There are fairly complete booths that can travel with the sales staff, on the airplane, as simple 'checked' baggage. I've seen a complete 12x20 set-up, that packs down to two duffel-bag sizes containers. around 50 lb each.

That said, one of the simplest, most reliable, methods of 'attachment' for repeated put-up/take-down, is the use of standard *hinges*. "Loose Pin" hinges, to be precise. Pull the pin, the pieces come apart. Line the pieces up, and insert the pin, and they're locked together. Add diagonal bracing for stability.

Another approach is "Tee nuts" in the material, and bolt-down "corner braces" and/or 'angle brackets'.

One of the other things to consider is tools and 'skill level' required for the put-up/take-down. And the amount of time involved. If you're going to 'big city' venues, you probably will *NOT* be allowed to do the unpacking/assembly/disassembly/packing work yourself. Union contracts will get in the way -- you'll have to use union labor for the task. Which means a need for comprehensive instructions for put-up/take-down.

[Martin]

Excellent links! Thank you very much.

The Invis system is really trick. I may just have to get the starter kit simply because of the cool factor.

-Martin

"mare" wrote >

[Martin]

I like the taper connectors, simple and effective.

-Martin

[Martin]

Thanks for the advise. Considering all the options at the moment.

-Martin

[Martin]

This is also interesting:

'm using the much larger version of this (by Southco) for the booth walls. I didn't know they were available this small.

-Martin

[Jon]

Have you ever considered door hinges? Remove the pins for easy takedown or fanfold.

[dadiOH]

One important consideration is the size of the horizontal piece. ______________

One handy thing that could work fine if there isn't tons of torque are the metal keyhole pieces.

Recessed into one piece and held by screws...round head screw in the other piece slides into the keyhole part (you can use several in each piece). They are inexpensive, easy to install, easy to break down and should be reasonably durable. You often see them used in "Scandinavian" case goods.

They could be improved by using a properly sized roundhead *bolt* (rather than screw) into a threaded insert.

-- dadiOH ____________________________

dadiOH's dandies v3.06... ...a help file of info about MP3s, recording from LP/cassette and tips & tricks on this and that. Get it at

[Patriarch]

"Martin" wrote in news:TkrYd.17430$ [e-mail]:

One other consideration is that, if possible, the hardware should be readily available locally to where you are shipping. In my trade show experience, parts go missing, get bent or broken, are loaded in the box that _didn't_ get shipped, require some tool that is only available with a three week order lead time, ....

Murphy hates trade show booth managers, with a passion.

In my experience, if there is any way that you can put it together with

1/4"-20 carriage bolts, fender washers and nuts or inserts, then do it. You can buy all the tools & parts at any hardware store or BORG, anywhere in North America, almost any day or night of the year.

Don't forget to plan for power distribution, lighting, cooling, voice and data connectivity, and secure material storage, while you're at it. DAMHIKT.

Patriarch