Teardrops n Tiny Travel Trailers

If I join two pieces of plywood usings biscuits, do the just glue together? Do I use finishing nails or something? Just biscuits and glue does not seem like it would be enough.

Also If I want recessed screws, so that I can use plugs to cover them. Is there a special drillbit for that?

Many thanks!

Shrug,
I'm not a woodworking expert, but here's my 2¢.
I've used the biscuit method a couple of times. Most of the glues available today create a bond that is stronger than the wood. The biscuits add strength and provide alignment of the joining surfaces. For cabinets and such, the biscuit method is plenty strong.
I use a "forsner bit" (may have spelled it wrong) for plugging. I start using the forsner bit, drilling deep enough the accept the screw head and the plug. Then switch to a regular bit and continue drilling to complete the pilot hole. There may be other methods, but it's worked for me.
Norm

Shrug,

Try looking at this link: http://www.rockler.com/ecom7/product_details.cfm?offerings_id=10607

You can get these at most home improvement or woodworking stores.

I have used biscuits for my projects for years. The typical joint is very strong and can withstand quite a bit, however, I would need to know where the joint is being put in your aplication to give you a better feel for the strength. If is is used to extend your sidewall on a teardrop and is supported with vertical bracing and and interior wall, I belive that is should be fine. You may want to use polyurethene glue (i.e., Gorilla Glue).

Just my opinion, but hope it helps.

Kerry

Thanks for the info. Yeah the join will be for sidewalls. 4x8 is just not big enough. I would like my sidewalls to be 5x10 but that seems an almost impossible size to find. When you do, it costs a heck of a lot more.

For countersinking screws, I've always just used a small bit for the pilot hole and then following that up with a drill bit the size of the screw head that only goes a little ways into the wood.

A little more work, but that's a good way to do it if you don't want to go out and buy more tools.

If I don't want to buy more tools? I don't understand. I know the words are english, but they make no sense in that configuration

Biscuits are meant to align your pieces of wood and when used properly, glueing the edge and into the biscuit cut, the biscuits expand and strengthen/secure the joint. Use the right size biscuit to fit your cut, I would, should I glue ply in this manner, not depend on the glue and biscuits alone but have a backer/ support built into the frame at this joint. Glueing with biscuits or scarving can not give the needed strength alone when used on plywood a multi layed edge. Biscuts and glued edges work fine on solid wood in the proper application.
There is a combination drill countersink in any decent tool section of Lowe's Home Depot etc. One hole one for the screw as a pilot and the second wider hole for the plug. Buy a plug cutter also and your plugs cut from scrap amtch the wood your plugging.

Shrug53 wrote:If I don't want to buy more tools? I don't understand. I know the words are english, but they make no sense in that configuration

You're not the only one. I started to twitch while writing that.

Glueing with biscuits or scarving can not give the needed strength alone when used on plywood a multi layed edge

I have made many scarfed joints, and when made properly, and the right adhesive is used and cured out properly, you can't beat the joint for strength or looks. Just a boatbuilder's opinion

I agree with Ol timer's opinion. A scarf joint is going to give you excellent strength. I'm a boat builder too. I think that for the average woodworker, it might be a little bit of a challenge for a joint that may be 4 feet long. I look at it this way. If it isn't going to be seen and is going to be covered with either aluminum or a laminate, I go with using a 3 wing cutter in the router. It cuts a groove 1/2 inch deep into each of the pieces. I then cut a spline in a good hardwood, and glue it up using epoxy. (butt joint with a spline).. It's like adding 10 times the biscuits depending on how you space them. It works for me as I overlayed the plywood with 6mil mohogany on the exterior and birch on the interior. I stretched my 4x8's into 4x10's and they are plenty strong. For me, I always have a tough time scarfing veneered plywood so that the grain matches up really well without sanding into the core. I'm still learning though. Doug Hodder

Hey Shrug, I extended my wall to 12 ft . Where the 8 ft met the 4ft section I installd a 1x2 poplar on the seam , glued & screwed all the way down the seam ,stagering the screws from side to side . After the glue was cured I filled in any voids with Elmers wood paste along with the counter sunk screws then sanded . You can only tell there was a seam there because of the filler. Other wise it seems to very strong. Have fun!

I had to build some 5X12' plywood for a project and I didn't think just a bisket & glue was strong enough either (though many experts said it was). So what I did was Rout a 1/8" slot in 1/2" Laun plywood, glue in an 1/8" spline to join the 2 pieces. Then laminate 1/8" Laun to each side, staggering all joints. 5X12X3/4 Laun...The Hard Way.

Happy Trails,

Len

My trailer's about 10' long, so a 4 x 8 wouldn't cut it. I built the sides from solid 3/4" ply, butt jointed together with wood glue and dowels. I already had a doweling jig and didn't want to buy more tools. Shrug, you're right: those words make no sense.

Anyhow, once the glue set the joint was strong enough that we could easily pick the piece up and move it around, no worries. I positioned the joint right at the galley wall and backed it up with a butt block, with a dado for that wall ploughed into the block. If I hadn't used a dado I would not have bothered backing up the joint.

Scarf joints are swell for boats, where you may be bending the plywood into a boat like shape, there's no 'hard spot' caused by the butt block. IMHO it's overkill for a straight, flat wall. Like Norm said, glues today are stronger than wood.

What a great long post. Bored at work today...