Bolt-together fiberglass Jeep-tub trailer kit

jscherb

Expedition Leader
#1
Earlier this year, I built a Jeep-tub trailer from the back halves of two tubs left over from my pickup projects:





The trailer has worked out great - I've already got over 2500 miles on it hauling future project parts home.

I'm very happy with the end result, but it was a challenging project at times. Even building a simple, small Jeep-tub trailer is beyond the means of most people - if you don't have a welder and some metalworking and bodywork skills, it would be tough to build this trailer or even a much simpler one.

Which got me to thinking - lots of people seem to want to have a Jeep-tub trailer to match their Jeep, what if it could be made easy for them? What if it could be a bolt-together kit? What if a set of fiberglass parts were made that would bolt together into a Jeep-style tub, and then could be bolted onto an inexpensive and readily-available trailer frame, like those from Harbor Freight?



So that's my current project. The goal is to make a "kit" of fiberglass parts that assemble easily into a trailer tub. I plan to make the kit a bolt-together one, meaning an average DIY-er could assemble a tub and trailer at home with average hand tools.

I'm in the process right now of building the molds to make the trailer tub parts. If you're interested in this project, please follow along and give me your input and ideas as I go through the project. If you've followed some of my other build projects, you know I really like to get your input and I often make changes and add features to what I'm building based on your input.

I'd especially like your input on how you'd outfit a trailer like this - like what features would you want built into it and what accessories would you want to go with it, maybe I'll build some of those features or accessories into the kit.

More to come...
 

jscherb

Expedition Leader
#3
More info on the design and plan:

I'm making the molds for the tub side panels so that they can be used to build sides of any length up to 8' (resulting in an 8' 7" long trailer tub), but by using "dams" in the mold, side panels of any shorter length can be made. For example, to go along with the $200 Harbor Freight mini-trailer frame, short side panels could be made for a 4' long trailer tub:



Eight foot long panels could be made to result in a trailer that could carry 4x8 sheets flat on the floor. Or panels roughly 7' long would be used to make a trailer tub that's the right size to fit the modular Safari Overland Camper top (here's the prototype work in progress, no windows yet):



Either an 8' tub or the slightly shorter one for the camper top would fit nicely on the 4x8 Harbor Freight Trailer frame:

 

jscherb

Expedition Leader
#5
Love the idea! Would love to have one. Is the HF trailer up to the task though? Especially in an off road environment?
Most HF trailers probably aren't up to heavy off-road usage, HF and similar frames would be ok for on-road and "improved trail" usage.

These tubs could be bolted onto any appropriately-sized trailer frame, so you'd likely want something more substantial for heavy off-road usage. Here's the frame I built for my yellow trailer, I used components to provide for a 3000-lb cargo capacity:



What I've tried to design is a tub kit that could be used for anything from a 4' long budget on-road trailer using a $200 HF frame up to an 8'+ offroad camper tub on an appropriate frame, it would be up to the individual to use these kit parts to build a trailer to their own specs.

 
#6
my input.
offer the option for different years, so the rear end mimics CJ, YJ, TJ, JK with correct placement of tail lights etc.

It would be sweet if you made one for XJ's as well that is shaped like an MJ (commanche) bed.

It would be REALLY sweet if you made aluminum and steel options not only for a more tough trail ready expo trailer but as well you could offer a kit that is ready to weld together instead of bolt up. I would personally prefer the weld up kit and I know a lot of people do know how to weld and they would prefer that, and even if they didn't know they may be willing to have a shop weld it for them, I don't feel that would have an adverse effect on the bolt up boxes. if so I feel it would be easier to make the weld up ones anyways because you are leaving out the bolt up tab locations.

mounting locations for a lid, and/or offer a lid option with mounting locations on the lid for a rack to incorporate a roof top tent.
could fab up a decent cargo box for the tongue....
 

jeepdreamer

Expedition Leader
#7
Hey! Welcome back JS! We missed you! :) I like the stand alone trailer thread...good idea. I wonder if you have any pics of hoe it mounts to the trailer? Close ups of how the bolts go through, reinforcment, etc?
 

jscherb

Expedition Leader
#8
my input.
offer the option for different years, so the rear end mimics CJ, YJ, TJ, JK with correct placement of tail lights etc.
The idea would be that the tailgate panels wouldn't be pre-drilled for tail lights; it would be up to the user to mount whatever lights he desired on them. And the tub will accept CJ, YJ or TJ tailgates, so you could install whichever of those you liked.

It would be sweet if you made one for XJ's as well that is shaped like an MJ (commanche) bed.
Could be done, but I don't have any plans at this time to do that.

It would be REALLY sweet if you made aluminum and steel options not only for a more tough trail ready expo trailer but as well you could offer a kit that is ready to weld together instead of bolt up. I would personally prefer the weld up kit and I know a lot of people do know how to weld and they would prefer that, and even if they didn't know they may be willing to have a shop weld it for them, I don't feel that would have an adverse effect on the bolt up boxes. if so I feel it would be easier to make the weld up ones anyways because you are leaving out the bolt up tab locations.
Check out the Aqualu aluminum trailer tubs, they're awesome.

My goal is to make a kit that can be assembled in a driveway with common hand tools that everyone would have. I also want it to be able to be manufactured in a very cost-effective manner, so it's within reach of almost everyone. Going to metal construction would significantly increase the price; going to weld-together metal construction would put it out of reach of the driveway DIY-er. Metal construction would result in a nice trailer, but I don't think it would meet the goals I'm shooting for.

mounting locations for a lid, and/or offer a lid option with mounting locations on the lid for a rack to incorporate a roof top tent.
I've done a design for a hard tonneau cover that flips open to form a tent platform; here's a drawing of it on a 4' trailer:



More about the tent platform later...

could fab up a decent cargo box for the tongue....
I've been thinking about that, you can see a tongue box in the drawing above.

Last year I worked with a box manufacturing company to produce an LJ trunk box, a photo of it is below (also in the photo is a prototype "soft barn door" I designed to make access to the back of the Jeep with the factory soft top a lot easier :) ). The LJ trunk box is now on the market (BTW fits nicely in Scramblers and JK's too).



I've got three thoughts about tongue cargo boxes:

1. I could work with the same company to produce a diamond-plate aluminum tongue box for the trailer.
2. I could make a tongue box from fiberglass
3. There are lots of trailer tongue boxes on the market already, even Harbor Freight sells two (on sale at the moment for $69.99 and $109.99).

At this point in the project I haven't made a decision about which way to go with tongue boxes.

Thanks for the input!
 

jscherb

Expedition Leader
#9
Hey! Welcome back JS! We missed you! :) I like the stand alone trailer thread...good idea. I wonder if you have any pics of hoe it mounts to the trailer? Close ups of how the bolts go through, reinforcment, etc?
If you're asking how the fiberglass tub will bolt to the trailer frame, I'll cover that when I get to that point in the trailer construction. I've got a design for it, but since I haven't finished the molds or built the first fiberglass tub, I don't have photos yet. It's a very straightforward design though.

My yellow trailer was built from Jeep tubs, so to attach that one to the frame I welded some standard-type body mount brackets to the trailer frame and just used factory body mounts. Also the trailer frame for that one uses a Wrangler rear crossmember, which had body mount holes in it already, so I used them. But for this trailer kit, in order to keep the bolt-together in your driveway criteria, I've got a much more simple idea. No welding of mounts to the trailer frame will be required.
 
#11
Well, since you asked...............:coffeedrink::smiley_drive::coffee:

A hard cover would be VERY NICE, including.....
-light cargo carrying capabilities (things in dry-bags such as clothing, sleeping bags, etc). I'm not so into roof-top tents (I know, blasphemy right?) so wouldn't need a great deal of weight carrying capacity on the top.
-easily removable by one person would be nice, for when you need to carry stuff taller than the trailer.

Perhaps the top could be split in the middle along the fore-aft axis, hinged along the port and starboard edges, and just opened up to form higher sides for those times when taller stuff needs to be carried. Ya, I like that idea.

Better yet (Woah, somebody STOP me!), offer the top as a few options...
1 - no top
2 - split on the fore-aft axis, hinged along port and starboard sides, with stops at 90 deg and 180 degree, and include a flat surface on the underside (which becomes the topside when opened 180 deg) for use as a work surface (ie - cooking, light mechanical work, folding and packing clothing, map recon, working on laptop, etc, the mind boggles...). A slight lip along the 4 edges when in work surface mode would help with things not being knocked off onto the ground. I'm not so sure I like that lip idea tho - might be nicer just flat. Ya, flat is better. Prolly need support legs angled back to sides of trailer. I'm not a fan of support legs to the ground because when/if the suspension compresses and the legs are to the ground you place stress on the work surfaces and/or hinges, or at least cause a tilting of the surface - the lawyers would not allow that tilting simply because of the liability from spilling hot coffee...:Wow1::wings:
3 - hinged along front edge, to fold 180 deg. and be flat over the top of the tongue (more stabile than hanging off the back end - would need support legs - again, not to ground) and include a flat surface on the underside for use as a work surface (see above words about work surface)

Provision for the home installer to add tie down points around the perimeter, preferably along the outside surface of each side near the top. Maybe large enuf so a few 6" lengths of Mac's Custom Tiedown Versa Tracks could be installed on the outside, with a matching length along the inside and the fiberglass side samwiched between for strength.

my $.02
 

jscherb

Expedition Leader
#12
Any rough price point estimate for all the fiberglass parts as above?
The short answer is "I don't know at this point". But I'll explain with a longer answer by covering a couple of points...

- My main design goal for this project is to create an economical kit that can be assembled by a DIY-er in his driveway with average tools. It's a kit so that it can have a less expensive initial purchase price and so the user can build it to his budget and performance specifications based on his choice of trailer frame. I do have a good estimate of the cost of the resin and fiberglass materials that will go into molding the kit parts, and those costs are very reasonable. My goal would be that a complete, ready-to-roll entry-level trailer could be built for between $750 and $1000, which would include the tub, trailer frame and everything else necessary to tow it on the street.

- I build these projects because I'm interested in the design and construction challenge involved, and when I initiate a project I typically don't have a plan to bring the project to market. So, ...at this point I do not have a company lined up to bring these to market. When I started the Safari Cab project I did not have a company signed up to produce them, and during the course of the project I was approached by a company and worked out an arrangement for them to have the rights to manufacture and market them. I'm approaching this project the same way - I'm building this because I'm interested in the project, and hopefully some company will be interested in producing them for the market. So far a number of my projects have become projects on the market already and one other is in the process towards becoming an available project (the Safari Cab), so the track record isn't too bad.
 

jscherb

Expedition Leader
#13
Well, since you asked...............:coffeedrink::smiley_drive::coffee:

A hard cover would be VERY NICE, including.....
-light cargo carrying capabilities (things in dry-bags such as clothing, sleeping bags, etc). I'm not so into roof-top tents (I know, blasphemy right?) so wouldn't need a great deal of weight carrying capacity on the top.
-easily removable by one person would be nice, for when you need to carry stuff taller than the trailer.

Perhaps the top could be split in the middle along the fore-aft axis, hinged along the port and starboard edges, and just opened up to form higher sides for those times when taller stuff needs to be carried. Ya, I like that idea.

Better yet (Woah, somebody STOP me!), offer the top as a few options...
1 - no top
2 - split on the fore-aft axis, hinged along port and starboard sides, with stops at 90 deg and 180 degree, and include a flat surface on the underside (which becomes the topside when opened 180 deg) for use as a work surface (ie - cooking, light mechanical work, folding and packing clothing, map recon, working on laptop, etc, the mind boggles...). A slight lip along the 4 edges when in work surface mode would help with things not being knocked off onto the ground. I'm not so sure I like that lip idea tho - might be nicer just flat. Ya, flat is better. Prolly need support legs angled back to sides of trailer. I'm not a fan of support legs to the ground because when/if the suspension compresses and the legs are to the ground you place stress on the work surfaces and/or hinges, or at least cause a tilting of the surface - the lawyers would not allow that tilting simply because of the liability from spilling hot coffee...:Wow1::wings:
3 - hinged along front edge, to fold 180 deg. and be flat over the top of the tongue (more stabile than hanging off the back end - would need support legs - again, not to ground) and include a flat surface on the underside for use as a work surface (see above words about work surface)

Provision for the home installer to add tie down points around the perimeter, preferably along the outside surface of each side near the top. Maybe large enuf so a few 6" lengths of Mac's Custom Tiedown Versa Tracks could be installed on the outside, with a matching length along the inside and the fiberglass side samwiched between for strength.

my $.02
Thanks, great input! I've got several preliminary designs for a hard tonneau/folding tent platform but I'll be finalizing them after I get the basic tub parts done. I like the idea that the hard tonneau could open to form a work surface.

Stay tuned, I'll want everyone's input on the "top" as I get to that stage in the project.

Also, I've been really happy with the soft tonneau I did for my yellow trailer, it's worked out great for my use of the trailer. But perhaps it isn't optimal for overlanding...



 

jscherb

Expedition Leader
#14
Once I finish making the molds, I plan to build a proof-of-concept trailer. My plan for the proof-of-concept trailer is to build a "short" one, with a 4' version of the tub. Originally I was planning to use the 40" x 48" HF Mini trailer as the base, but I decided I wanted to build this first trailer on a heavier-duty base, so I'm going to use the HF 94564 Heavy Duty 4x8 trailer - it's got a 1720-lb. payload capacity, and a 5-on-4.5 bolt circle, which is the same as the TJ/YJ Wrangler. Here's a photo of the HF 94564:



The trailer will have to be shortened from it's 8' length into a 4' length; this can be done as a simple "drill job", meaning the only tool other than wrenches and screwdrivers that will be required to do the mod and assemble the trailer in the shorter size is a drill, to make a few new holes necessary for the new configuration. Here's how the conversion to a 4'x4' trailer will be done:



The trailer comes as two 4x4 foot frames bolted together in the center, so it will be assembled with only the front frame. The axle mounting bracket will be moved forward to position the axle just behind the center of the shorter frame, and the rearmost tongue brackets will be eliminated and the back ends of the tongue will be secured to the front spring hanger bolts.

I also have a use for some of the pieces from the back part of the frame that won't be used - one of the leftover beams will be turned into a mount for a rear hitch receiver, so receiver accessories like bike racks could be used on the trailer.

My goal is to build the trailer as if I'm a typical DIY-er in his home garage, without access to and special tools. So the build will be a proof-of-concept of the bolt-together capability of this tub along with the HF trailer frame.

BTW, once the proof-of-concept trailer is complete, I may offer it for sale. Since I've already got a Jeep-tub trailer, I don't think I need a second one.
 
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