Teardrops n Tiny Travel Trailers

To attach the walls to the floor should I use bolts or deck screws? the floor is a 2 by 4 frame with 3/4 in ply on top. I'm leaning towards the screws because I don't want to worry about bolts again and it's cheaper to buy a box of screws I'll use for other things than spending a bunch on bolts and washers and nuts.

Floor to trailer bolts, walls to trailer deck screws!

Cliff

CliffinGA wrote:Floor to trailer bolts, walls to trailer deck screws!

Cliff

Ditto..... Glue helps too... Maybe something like "Liquid Nails" (brand) in caulking gun....

Dale

If I'm attaching to metal, and I have access to both sides, I always use bolts with locktite. If its wood to wood, the longest screw that will fit. :-)

I am attaching the floor to 35mm x 70mm timber with 12 Gauge screws. The 35mm x 70mm floor bearers will be attached to the steel frame with 1/4 UNF -28 bolts that I will make myself. To buy the bolts would cost me over $148.00 which is simply not on. I can buy the steel as bright Mild Steel (it's precision in diameter and medium high tensile) and make all my own bolts for under $10.00 including longer length nuts. The sides will be bolted to the steel RHS with the same bolts and also screwed into the 30mm x 70 timber. All the bolts can be made is less than a day and are fun to make. I would have them all made now but I have to wait another five days for the steel to arrive from Brisbane through the flood zone. I can wait, no problem, the people in Brissie come first.

Kody

If its bearing weight, I recommend bolts if you can get to both sides.
Tom

I used stainless steel trailer deck screws at 6" on center. Even though they are self- drilling and self-tapping I pre- drilled through the floor into the trailer frame. This method is quick, easy and strong.

Kody wrote:To buy the bolts would cost me over $148.00 which is simply not on.

How many bolts are you intending on using?!?!

My trailer sides are solid 3/4" MDO plywood (5'x10'), with the factory style doors. They aren't light by any means! And I have maybe 10 bolts across the bottom of each side to attach to my trailer, which is probably overkill. Cost maybe $20-25 for all the hardware - probably not even that much!

I used 2x4's fastened to the sides of my trailer (with bolts) to extend the width a few inches. I attached the walls to those using deck screws and Loctite PL Premium.

Keep in mind that there is only a single 1/2" or 5/8" diameter pin that keeps your trailer hitch - and your teardrop trailer, standy, etc. - tied to the receiver of your tow vehicle.

aggie79 wrote:Keep in mind that there is only a single 1/2" or 5/8" diameter pin that keeps your trailer hitch - and your teardrop trailer, standy, etc. - tied to the receiver of your tow vehicle.

Are you alluding to the fact that there may be some overkill in some of our builds, Tom???

aggie79 wrote:Keep in mind that there is only a single 1/2" or 5/8" diameter pin that keeps your trailer hitch - and your teardrop trailer, standy, etc. - tied to the receiver of your tow vehicle.

Yup, and that little 5/8 dia hitch pin (0.307 cross sectional area) can take about 14700 of force in double shear before thinking about failing. But we must remember that a receiver hitch is specifically designed to only put shear (and some impact) loads on the pin. The bearing and torsion loads are transmitted through the receiver tube, distributing them over wide lever arms to the hitch frame and onto the TV.

Here is more than you ever wanted to know about metal fasteners and wood joints.

I can't be bothered to work through all that. The TLAR method says use glue and spread the fasteners out evenly to develop the overall strength of the structure.

For the wall to floor join, my walls will be glued on top of my floor and will be screwed every 10 to 12 inches using wimpy looking Kregg screws. The counter bores for the Kregg screws will be sealed and filled, then the outer canvas and paint skin (or glass reinforced epoxy... haven't decided yet) will be wrapped down the wall and under the floor.

I've got (16) 3/8 inch bolts to hold the floor to the trailer frame, (12) of which are spread evenly around the perimeter, and (4) equally in the field. These screw up (through tabs and angle xmbr's in the trailer frame) blindly into threaded inserts that were embedded into the floor frame from the top before the top floor skin was applied. I also plan on bedding the cabin into sealer applied to the tops of the trailer frame members. This is mostly for water exclusion, but will add quite a bit of adhesive strength, as well.

Between the walls being glued to the floor, the outer skin wrap being fully "glued" to the whole cabin (sock effect on roof, walls and floor) and the wrap being captured between the cabin and trailer, the handful of Kregg screws are really only there to keep things aligned and tight during glue up.

Granted TPCE is a hybrid construction, but my point is that it is the sum of all the little strengths that add up to that 14700 lb. capacity.

Okay, I know that the math doesn't necessarily translate directly that way, but by building up the strength through distribution using light weight methods spread over large areas, you will create an amazing strong structure out of seemingly weak components. Don't assume that you need a bunch of huge fasteners. The glue is where most of the joint strength comes from.

This Spirit Of St Louis replica wing is made up from thin ply, tiny dowel pins and glue... no bolts or screws at all (okay, there are a couple of wire stays for tensioning). Any one of these components could be snapped like a twig in your hand, but together, in the proper orientation, they take a huge load and transfer it efficiently.


Is anyone sick of seeing this pic? I'm not.

Wow thanks all for the response glue and screws it is for me

aggie79 wrote:I used stainless steel trailer deck screws at 6" on center. Even though they are self- drilling and self-tapping I pre- drilled through the floor into the trailer frame. This method is quick, easy and strong.

My flatbed trailer has steel self drilling and tapping screws holding down the 2x6 planks. Only a couple have come loose after 25 years. Use enough and it won't be an issue.

If your frame is an angle iron one, you could put the screws into the wood from the bottom. Then you could use standard screws.

One suggestion I didn't see was to use a combination. Bolts at the corners, and screws everywhere else. This gives you strong bolts to bear the weight, but the ease of screws and lots of them to keep the sides in tight.
Tom