The Geek's Lair

[Wolfgang92025]

Geekfisher,

My plans came out of the design library in the top header, It is a modified 2&2 High.
Link to my build.... http://www.tnttt.com/viewtopic.php?t=28640
In my opinion, the only chance you have for a 1000# trailer is a full Foamie and a support structure for the roof tent.
Try to think/design along the lines of an aircraft, not a tank. I know, easier said then done.

[KTM_Guy]

My cross members are a mix of 2X2 X1/8 angle and 1X2 12 gage tube. That space in the middle is where future water tank will be. Abour 30 gallons. Centered over the axle.

Size your roof spars for your insulation. The roof rack typically mount to the side wall. Make sure you have solid backing to have something to screw into. A stud should be under the backing down to the floor. Did you say how you are building your walls? Stick built or skeleton method ?

If you are wanting to be 1,000-1,2000 pounds finished weight for a trailer that size you need to thinking “ultralight” ALL THE TIME. Instead of using 3/4” wood ask yourself can I use 1/2” or 1/4”. Weight adds up fast.

Todd

I expect to use 1-1/2 thick Isoclad stuff (foam with air barrier) for everything except maybe the floor so 2x2 made sense when I designed. I don't know the difference between skeleton and stick build. I thought about going kinda house-like, studs every 16in centers (when possible...) with studs where the partition wall will be since I plan on insulating this wall but not the galley walls as it doesnt need it. Roof spars would be cantilevered on the side walls if that makes sense (it might not, in the end...)

I don't want to use anything thicker than 1/4" for plywoods. Here is where I am so far:

• 1/4 outside and 1/8 inside for sidewalls.
I used 1/4 both inside and out. 1/8" isn't much if you have to attach things like hooks to the wall. Try to pre think stuff like that and add backer.

• 1/8 at the very bottom and 1/4 on inside floor
I did 1/8" top and bottom. Nest time I will do 1/4" bottom and still 1/8" top side. I'm thinking something on the road or trail could damage the 1/8 more so 1/4". You don't walk on the floor and the mattress spreads and distributes the weight.

• 1/8 roof and ceiling
I did the same.

I built using the skeleton method, you build the wall skeleton just putting wood where it is needed. Cut insolation to fit.



Then add any wiring and backing, and the inside skin and the outside skin to create a wall panel. The wall is epoxied on the outside and the inside wall is varnished before it is put up on the floor. If you don't know about the inside out method of building you should check into it because it really makes it easier to build. Build you walls, then the floor, put walls on floor. Then build out the inside, after the inside is done the ceiling get installed already varnished or painted. then the roof spars, wiring, insolation, and finally the roof. If done right you don't have to keep climbing in and out the cabin through the door. And you don't have to varnish in a small space. If you look at my build you can see I put up one wall and then installed all my cabinet that were pre made before I put up the second wall. The other thing I did that I saw on on Tony's build is to not build on the frame but on a 2X4 frame on casters. It made it so easy to work on the roof and to get in and out to work on the inside.

[GeekFisher]

@KTM_guy
I am reading (again !) your build thread, will probably finish the reading tonight.

I didn't plan on using outside walls to mount stuff, except some hooks to hang coats. Everything else is embedded in cabinets or "mini" night table. As for the building, I feel my first challenge will be the bunk bed. I will likely put the front wall after almost everything else so I will always have a large opening to put stuff in the trailer. Is that a good idea ? The second challenge will be cabinets as I never built any. Third challenge will be doors, especially the hatch galley door. Which asphalt coating did you used ?

[GeekFisher]

300w 12v heater is 25 amps, 100AH battery taken to 50% gives you 2 hours of run time, as long as you don't use any other power. It just doesn't make sense to make heat out of 12v battery power. Look into a Little Buddy heater or better yet one of the Chinese diesel heaters that has combustion air.

Todd

I seriously started looking over these over the week-end and after thoughts, it might be the better solution. I can make it swappable with the A/C for vent ducts. I also did the math for most of the wood. I have yet to do the math for the trailer frame and will likely go pick up the steel this week.

[Andrew Herrick]

Your proposed use of an exterior WRB (Tyvek) is dependent on a dozen other factors. It's not a yes-or-no question. There are very few situations where it would hurt, but quite a few where it would do no good. What's more important than a continuous WRB is that you flash all penetrations and openings (hatches, windows, fans, doors, etc.) so that any intrusive water is redirected to the exposed interior wall and NOT into the wall cavity. In a camper, the humid air is usually the interior air, so you might be better off installing Tyvek on the INTERIOR-side to prevent warm, humid interior from migrating into the wall cavity, hitting the cold exterior, and condensing into bulk water INSIDE your wall. A WRB on the exterior isn't normally harmful, but since camper exteriors (unlike a house) aren't designed to dry from the outside, the uses of a continuous exterior WRB are limited.

[GeekFisher]

Your proposed use of an exterior WRB (Tyvek) is dependent on a dozen other factors. It's not a yes-or-no question. There are very few situations where it would hurt, but quite a few where it would do no good. What's more important than a continuous WRB is that you flash all penetrations and openings (hatches, windows, fans, doors, etc.) so that any intrusive water is redirected to the exposed interior wall and NOT into the wall cavity. In a camper, the humid air is usually the interior air, so you might be better off installing Tyvek on the INTERIOR-side to prevent warm, humid interior from migrating into the wall cavity, hitting the cold exterior, and condensing into bulk water INSIDE your wall. A WRB on the exterior isn't normally harmful, but since camper exteriors (unlike a house) aren't designed to dry from the outside, the uses of a continuous exterior WRB are limited.

Thanks for the reply. I also plan on a vapor barrier right on the inside part of the 2x2, over the insulation but before the finishing plywood/luan. We have -30 to 105 temps around here. Very humid in summer but relatively dry Spring Fall and Winter. The TD will be used from 0 to 105. A/C and heating will likely share the same duct vents. I tried to limit the amount of humidity inside that way.

BTW I bought the steel yesterday

[noseoil]

I went with 1/8" for the inside floor & 1/8" for the bottom as well, with 3/4" poplar for the framework & 3/4" foam insulation in the voids. In the end, I chickened out about the 1/8" skin for the inside & added a small 1/4" panel, which just sits in the opening for the door area where your backside enters first. It spans the entire width & is about 2' wide. With a thick mattress, sleeping is no trouble, but sitting down was a bit worrisome, so the extra 1/4 in that area is cheap insurance. The walls were 3/4" plywood skeleton panels with 1/8" skins inside & out. Plenty strong! Hard points were just 3/4" blocks where needed for attachments.

I used a 2000# axle which came with the trailer originally, but after a trip to the scales two years after the build (1660# empty) & some uneven tire wear after 16000 miles, went to a 3500# axle with brakes. The frame was heavier than necessary (550# with tongue box), but it's been a good build for us & many miles of towing later it's still solid.

I would think about the overall weight, especially if you add a water tank and things are stowed, added & in general made heavier than expected. A heavier spring rating & axle might be in order...

[GeekFisher]

Some progress today !

[FM82]

That bunk area is very cool. I agree with adding in a fan though. Awesome build plan! Following.

Sent from my XT1650 using Tapatalk

[GeekFisher]

Quick update and questions.

I finally ordered a 3500lbs axle w/ electric brakes but 2500lbs springs as I do not want the trailer bouncing on our degraded QC roads. 72in hubface and 60in spring center so that part is worked out. I also ordered the A coupler with a strenghtening underplate. I bought a bunch of clamps, deck screws (different lenghts) and tubes of PL premium and PL 300 (for foam boards)

I also went in to look for lumber. 1/8 is not that common but 5.2mm which stands between 1/8 and 1/4 (just shy of 0.21) is widely available and seems pretty nice so I might be inclined on going with that instead except for interior skin which would be 1/8 (or 2.7mm depending)

I also found an epoxy supplier in the area so I'll be able to glass floor, side and roof. I was also wondering which type of asphalt coating should I use for the undercarriage ?
Fibrous roof coating or non-fibrous roof coating or non-fibrous foundation coating ? I feel like fibrous would hardened the wood a little bit and since I'm using thin stuff this is appealing. Any thought about that ?

Also, after reading too much stuff about it, I decided to get rid of both the vapor barrier and the WRB (Tyvek/Typar kind of white canvas)

I feel that these are not needed with rigid foam with epoxied walls. I will tape the foams to the 2x2 studs though. Do I need foil tape or duct tape will just do fine ?

Thanks all for your very useful replies to this point and your indulgence with a newbie like I am ! Very appreciated and can't wait to get back to work

[Andrew Herrick]

I also found an epoxy supplier in the area so I'll be able to glass floor, side and roof. I was also wondering which type of asphalt coating should I use for the undercarriage ?
Fibrous roof coating or non-fibrous roof coating or non-fibrous foundation coating ? I feel like fibrous would hardened the wood a little bit and since I'm using thin stuff this is appealing. Any thought about that ?

Also, after reading too much stuff about it, I decided to get rid of both the vapor barrier and the WRB (Tyvek/Typar kind of white canvas)

I feel that these are not needed with rigid foam with epoxied walls. I will tape the foams to the 2x2 studs though. Do I need foil tape or duct tape will just do fine ?

Thanks all for your very useful replies to this point and your indulgence with a newbie like I am ! Very appreciated and can't wait to get back to work

Fibrous roof coatings are stronger, but less elastic. Non-fibered roof coatings are more elastic, but less strong. Pick your poison .... In actuality, an elastomeric roof coating is your best bet. They are 2-3x more expensive, though. If you go with a cheaper asphalt emulsion roof coating, you might wind up with hairline cracks in your first coat after a year or two, but it's not hard to touch up with a second coat.

Taping the foams to the 2x2 studs is an excellent idea. Foil or duct tape, well, isn't lol. Foam, especially low-density insulation foam, shrinks. And while lots of tapes have decent initial tack to the foam, most won't hold more than 24-48 hours, ESPECIALLY after exposed to thermal and/or humidity cycling. Thankfully, there are tapes specifically designed to bond to rigid foam insulation. 3M 8087 and 3M 8067 are my favorites.

[GeekFisher]

Fibrous roof coatings are stronger, but less elastic. Non-fibered roof coatings are more elastic, but less strong. Pick your poison .... In actuality, an elastomeric roof coating is your best bet. They are 2-3x more expensive, though. If you go with a cheaper asphalt emulsion roof coating, you might wind up with hairline cracks in your first coat after a year or two, but it's not hard to touch up with a second coat.

Taping the foams to the 2x2 studs is an excellent idea. Foil or duct tape, well, isn't lol. Foam, especially low-density insulation foam, shrinks. And while lots of tapes have decent initial tack to the foam, most won't hold more than 24-48 hours, ESPECIALLY after exposed to thermal and/or humidity cycling. Thankfully, there are tapes specifically designed to bond to rigid foam insulation. 3M 8087 and 3M 8067 are my favorites.

Thanks for your reply !

Insulation tape readily avail is http://www.canac.ca/en/product/building ... ite=001002 it is made for insulation. The insulation I'll be using is blue or pink foam (depending on which brand I choose)

Would elastomeric roof coating give any strenght ? Because it's almost $=$ with Epoxy so might go epoxy all the way around ? Also, if I plan on skinning in aluminum, do I need to seal exterior walls ? I planned on sealing the roof with Epoxy anyway but was unsure about exterior sidewalls.

Thanks,

[Andrew Herrick]

Thanks for your reply !

Insulation tape readily avail is http://www.canac.ca/en/product/building ... ite=001002 it is made for insulation. The insulation I'll be using is blue or pink foam (depending on which brand I choose)

Would elastomeric roof coating give any strenght ? Because it's almost $=$ with Epoxy so might go epoxy all the way around ? Also, if I plan on skinning in aluminum, do I need to seal exterior walls ? I planned on sealing the roof with Epoxy anyway but was unsure about exterior sidewalls.

Thanks,

No, elastomeric roof coatings add no strength. To be honest, not a single liquid-applied coating besides epoxy will. And I'm not sure where you're buying epoxy, but you can get a 5-gallon bucket of elastomeric roof coating for $70. You'll be hard-pressed to get a single gallon of epoxy resin for much less.

As far as sealing walls go ... eh, depends who you ask. Some people epoxy the whole build; some people assume that if the aluminum skin does its job, any more sealing is just a waste of time and resources. Depends how many suspenders and belts you want to add. So long as everything is taped and flashed properly, I wouldn't (based on my limited knowledge of your build) feel the need to epoxy the sidewalls. If you're particularly sensitive to mold, maybe consider a mildewicide primer/paint on the 2x2 wooden frame ...? Just spit-balling there, though.

[KTM_Guy]

I used epoxy on the floor. Inside and out.

I agree with Andrew on now needing to epoxy the walls with an aluminum skin. But I did it anyway. to me it’s cheap insurance.

Todd

[redbicycle]

I also found an epoxy supplier in the area so I'll be able to glass floor, side and roof. I was also wondering which type of asphalt coating should I use for the undercarriage ?
Fibrous roof coating or non-fibrous roof coating or non-fibrous foundation coating ? I feel like fibrous would hardened the wood a little bit and since I'm using thin stuff this is appealing. Any thought about that ?

Since you are already buying epoxy for other uses why not use epoxy on the floor. Using roof coating instead is fine, but you are buying more materials and you will have waste in the leftover from whatever size you buy (gallon?) vs what you need. With the epoxy you are using the same material across many part's of the build. This is the path I decided to take. Good luck!