New member, new trailer design!

[Pmullen503]

the entire box will be sealed with epoxy...

I'm not convinced epoxy alone will prevent the plywood from checking. Adding either 4 oz or 6 oz fiberglass cloth is cheap insurance.

Tony

+1 to adding cloth. The wood plys not saturated with epoxy below the surface will continue to expand and contract with temperature and humidity leading to checks. Compared to paint or varnish over bare wood, degraded epoxy saturated wood is much more work to refinish.

Epoxy alone compared to epoxy+glass cloth has nowhere near the longevity and doesn't add appreciable strength.

 

[saywhatthat]

I have found with the litte heaters. you may never need .BUT run air over what you will have on priceless. will dry out inside of small trailer

 

[reaver]

the entire box will be sealed with epoxy...

I'm not convinced epoxy alone will prevent the plywood from checking. Adding either 4 oz or 6 oz fiberglass cloth is cheap insurance.

Tony

+1 to adding cloth. The wood plys not saturated with epoxy below the surface will continue to expand and contract with temperature and humidity leading to checks. Compared to paint or varnish over bare wood, degraded epoxy saturated wood is much more work to refinish.

Epoxy alone compared to epoxy+glass cloth has nowhere near the longevity and doesn't add appreciable strength.

Whelp, I guess that means I lay down fiberglass as well. How much do you think I'd need, and what's a good recommendation for a product to use? I've never laid down fiberglass in my life, so I'm not sure what to use, or how much of it to use.

 

[Tony Latham]

How much do you think I'd need, and what's a good recommendation for a product to use?

I would recommend Raka's non-blush six-quart kit.

https://raka.com/product/non-blushing-epoxy-kits/

Order their pumps at the same time. For glass, order either their 4 oz or 6 oz. Depending on your wall and width.

https://raka.com/product-category/woven-fiberglass-cloth/

Grab a couple of their squeegees and mixing sticks you're good to go.

The trick is to mix small batches, otherwise, it'll go off in the pot.

From my book:

The key to this process is mixing small batches. Epoxy is strange stuff. As soon as it is mixed, it starts producing heat, which grossly speeds up the reaction. After mixing a batch, you’ve got about ten minutes if it remains in the container. But once it’s poured onto the cloth, you’ve got a long time. I would suggest keeping the batches to no more than about a half-cup. My six squirts per batch worked out to be about 5 ounces. Make sure you or your assistant aggressively stir each batch for two minutes. During stirring, you are really only mixing the center of the liquid so make sure you scrape the resin off the sides of the container as you mix.

Pour the epoxy onto the cloth in thick lines and use a plastic squeegee to disperse it. Just work slowly, and methodically. Once the resin is out of the container, there is no need to rush.

As you wet out the cloth, keep in mind that some of the epoxy will absorb into the wood, which can lead to resin-starved fiberglass. The squeegee is your stethoscope. It will vibrate over starved cloth and glide over areas of excess epoxy. Keep looking at the layup from a low angle for dull or shiny spots. If a spot looks whitish, it needs more resin. Properly saturated cloth is transparent. Adding resin to saturated cloth doesn’t increase the strength.

Pay attention to the edges of the wall and ensure you have good saturation. If you have a raised spot in the fiberglass, work it flat with the squeegee.

When you think you’re done, take a twenty-minute break and then check to make sure that some of the cloth hasn’t lifted. You can push those spots down with the squeegee. Additional epoxy can be added as long as it’s still tacky.



I recommend doing the walls while they're flat on the bench.

https://youtu.be/BJZYGY2he1o?si=bLfB2R347j7mPAlq

Tony

 

[reaver]

OK, since I'll now be fiberglassing, any tips you can give me for the best method? I'm not worried about finish, since I'm still planning on skinning with acm. I prefer the look over bedliner, and it's slightly cheaper than painted aluminum sheets, while having the same finish.

 

[Tony Latham]

OK, since I'll now be fiberglassing, any tips you can give me for the best method? I'm not worried about finish, since I'm still planning on skinning with acm. I prefer the look over bedliner, and it's slightly cheaper than painted aluminum sheets, while having the same finish.

There are a ton of videos concerning fiberglassing over wood on Youtube. Do a search for 'fiberglass wood strip canoes' to start.

But there are two philosophies, coat the wood with epoxy first and while it's still tacky, add the glass vs. put the glass on and squeegee the resin into it. The latter works well for me. Keep in mind the wood will suck resin out of the glass. You want it saturated, but not much more. Your squeegee is your stethoscope.

Tony

 

[Pmullen503]

I always lay the glass down, smooth it out and apply the epoxy and "scrape" which means use some type of squeegee to press the cloth to the wood and remove excess resin. The next coat or two applied with the first coat not fully set.

I can't see how trying to apply glass to a wet surface would work unless the area was pretty small. How would you smooth out the cloth?

 

[Tony Latham]

I can't see how trying to apply glass to a wet surface would work unless the area was pretty small. How would you smooth out the cloth?

I agree, but it's done, and some advocate for it.

Tony

 

[reaver]

What I'm seeing based on research, is that it's much easier to apply the cloth to a dry surface, then coat the cloth with epoxy, while squeegeing it down. Then coat again with a second coat of epoxy. This seems like the easiest way to do large surfaces. I'm also planning on wrapping the fiberglass around the cutouts for doors, and the fan opening. This should prevent almost any chance of water getting down into the framing of the walls.

Now, I'm going to need pass through areas for tail lights, porch lights, and all that jazz. What's the best way to seal the wood up on these holes as well? Getting fiberglass in there will be exceptionally difficult (if not impossible).

 

[saywhatthat]

as you're doing a squaredrop why not a fiberglass panel? no water. no time-wasting frame? If the gap is not that tight no big deal. 50% are more faster to build .lighter.
Harder to tie a shoe than the trailer build. If any damage a few bucks to fix. Under $100 in tools . Too build. Just need panels. DIY fiberglass angle, glue, pop-rivets. A few can foam to blow up the seams
The glass angle on the outside makes the frame. with the 2-inch wet lay up on the inside part of the frame then you fill the gap with can foam makes a strong flexible frame for hard inpack. To build. Cut side profile . tape top panales in .Add angle outside glue and pop rivets on . Can remove rivets after glue drys . Do a 4inch wet lay-up inside seam then fill with can foam

 

[saywhatthat]

..

 

[reaver]

as you're doing a squaredrop why not a fiberglass panel? no water. no time-wasting frame? If the gap is not that tight no big deal. 50% are more faster to build .lighter.
Harder to tie a shoe than the trailer build. If any damage a few bucks to fix. Under $100 in tools . Too build. Just need panels. DIY fiberglass angle, glue, pop-rivets. A few can foam to blow up the seams
The glass angle on the outside makes the frame. with the 2-inch wet lay up on the inside part of the frame then you fill the gap with can foam makes a strong flexible frame for hard inpack. To build. Cut side profile . tape top panales in .Add angle outside glue and pop rivets on . Can remove rivets after glue drys . Do a 4inch wet lay-up inside seam then fill with can foam
View attachment 2 View attachment 1

While I understand that pure fiberglass panels will be exceptionally light, that is NOT the finish I'm going for. I may look into figuring out how to build some sort of foam/fiberglass composite down the road, but for right now, wood backed is the way for me to go.

That being said, since I'm fiberglassing, I maybe do the sides in 1/4 in ply for weight savings. If I keep the only 1/2 in panel to the exterior of the floor, this should really help with weight savings. I think if I add a 1x2 furring strip down the middle of the floor, so I have a grid of foam and 1x2's sitting on the 1/4 in floor, that should be plenty of support for my 6 in mattress.

 

[saywhatthat]

1x2 furring strip down the middle of the floor, so I have a grid of foam and 1x2's sitting on the 1/4 in floor, that should be plenty of support for my 6 in mattress. Yes that will be great. With the matters spreading out the load . A little flex in the floor does not hurt anything. Any inside bulkhead help so much also. the door jams add a lot of support to the walls

 

[reaver]

Ok. I've been working on learning Sketchup, and trying to work out how best to put this together.

This is what I've come up with for the cabin:

I can't seem to figure out how to do a 2x2 spar roof to get the support I'm looking for, without doing 1.5 in insulation. So.....the roof and the front walls will get 1.5 inch insulation. The walls and floor will get .75 inch insulation.

Unless I'm completely off base here, I think this thing will be very solid.

Door center is 28" from the front wall. Doors are 24" wide. The exterior dimensions of the cabin will be 96" long x 60" wide, prior to fiberglass/epoxy followed by bedliner. All plywood is 1/4", with the exception of the outer floor board. This will be 1/2", and will be sitting on an expanded steel mesh on the trailer.

 

[ghcoe]

You will want to move the door back farther if you can. It will make it easier to get into the bed without scooting.

 

[reaver]

You will want to move the door back farther if you can. It will make it easier to get into the bed without scooting.

I absolutely have room to move it back. I measured and came up with 26 inches from head to hip. I wonder if I put the center of the door 32 inches from the front of the trailer, if that would work.

Also, I realized as I was trying to place the mattress.....that the original design was done with the trailer being 48 inches wide!! Doh! Currently fixing that as well.

Edit:

I didn't realize that I had created the initial design at 4x8 dimensions. I've adjusted the design, and can now fit my 58x78 inch mattress inside.

 

[ghcoe]

You will want to move the door back farther if you can. It will make it easier to get into the bed without scooting.

I absolutely have room to move it back. I measured and came up with 26 inches from head to hip. I wonder if I put the center of the door 32 inches from the front of the trailer, if that would work.

You want to be able to sit in the doorway and then pivot on you butt into the sleeping position with little to no scooting. Are your heads going towards the front or towards the back. It can make a bit of difference, but not by much.

I just measured mine and it is 33" from the center of the door to interior wall. 32" would probably work fine for you.

 

[reaver]

You will want to move the door back farther if you can. It will make it easier to get into the bed without scooting.

I absolutely have room to move it back. I measured and came up with 26 inches from head to hip. I wonder if I put the center of the door 32 inches from the front of the trailer, if that would work.

You want to be able to sit in the doorway and then pivot on you butt into the sleeping position with little to no scooting. Are your heads going towards the front or towards the back. It can make a bit of difference, but not by much.

I just measured mine and it is 33" from the from center of door to interior wall. 32" would probably work fine for you.

Thanks George! You are a little bit taller (and much skinnier) than I. 32 should work well then.

 

[reaver]

I've been refining my design over the last couple days. I think I've got the basic layout of the galley figured out, as well as where all the electrical components will go.

Galley Layout

Cabin Layout

Sidewall Framing

Overall Design

I had to adjust the angle on the front of the trailer. The solar panel I've chosen hung over the angle. Which, if I didn't want that front box there (which is where the fridge will live), it wouldn't be a big deal.

So, I made the angle not as steep to accomodate the fridge box, and the solar panel.

In the galley, I've layed out all my electrical devices, and the diesel heater. I'll put the diesel heater on a mounting plate that goes through the floor, and seal it all up using high temp sikaflex or something like that. I'll be recirculating the heater through the cabin so that it's not always blowing in cold air. I'll build a shelf on top of the heater to put the battery (it doesn't weight terribly much due to being lifepo4). DC-DC and solar charger will be on the wall between the battery compartment and the storage to the left.

As far as lower storage, I've not decided if I want drawers down there, or shelves, or a mixture. I'll have to consult the wife to see what she thinks would be best for that.

Up above, will be my Progressive Dynamics PD6000 Distribution panel, along with the display for the battery monitor, solar charger, and a secondary control for the stereo I'm planning on putting in the trailer.

I've started ordering parts.

Today, fedex showed up with the first of the hatch doors.

This one is for the kitchen box (the blue box on the side of the trailer). I'm trying to mimic what off grid trailers does with their kitchen:

I just ordered the doors for the front fridge box. The box will be plenty big enough to house a 60L fridge, maybe even bigger, depending on how wide it is. The opening of the doors I ordered is 30x20, so most fridges should fit through there.

 

[Pmullen503]

Nice design. I have a couple suggestions for better aerodynamics. First, consider inseting you stove box so it's flush on the outside. You lose some cabinet space but you just have a door instead of a box hanging in the wind. Second, narrow the very front of the fridge box so it's narrower than the width of the tow vehicle if it isn't already.