Coast Resorts Open Roads Forum: Avion truck campers

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Topic: Avion truck campers - Hundreds of photos

Posted By: ticki2 on 03/29/13 11:03am

Mine had the same small charger as 69Avion . It was located under the hatch of the dinette floor next to the battery box. I replaced it with an Iota 3 stage converter/charger and located it in the same place .

'68 Avion C-11
'02 GMC DRW D/A flatbed

Posted By: Jamm3r on 04/07/13 09:56pm

Well folks the greywater tank project has mushroomed into a water project affecting pretty much everything. I had a leaky joint in the ABS drain plumbing that required a good deal of replumbing to fix and so I ended up doing everything before I stopped.

Also leak checked the toilet tank and was glad I did. I had repaired it in place last year, and since everything was apart anyway I pulled it out for more thorough repairs. It's the original Thetford tank, made of Styrene or ABS or some similar plastic.

It has a bunch of cracks and has been repaired at least four times already, counting my efforts last year.

So, I took a look around. There are three reasons why these things fail:

1) The tank isn't adequately secured in place, so, when the camper is moving, there's a great deal of stress on the bulkhead fittings since they end up being what holds the tank down. This is worse the more******there is in the tank.

2) The stock dump valve plumbing is rigid and isn't adequantely secured in place, so it has a sort of lever effect and flexes the tank too much.

3) The tank walls are just too thin.

I ground off most of the old repairs and am in the process of sealing the cracks from the inside with epoxy and reinforcing the outside with fiberglass fabric and marine epoxy.

[image]

1971 Cayo C-11 truck camper, 2010 Airstream Classic, 1997 Chevrolet K2500, 2004 Chevrolet Suburban 2500 8.1.

Posted By: Jamm3r on 04/07/13 09:59pm

The last photo is of the interior of the tank showing some of the cracks.

I'll post some repair pics.

The back-to-back Thetford flanges appear to be a sloppy repair from some point in the past. I'm switching to the more readily available Valterra valves as part of the repair since I'm going to be fiberglassing on a new flange anyway.

Posted By: HMS Beagle on 04/07/13 10:20pm

I don't know what plastic you are dealing with, but if it is one of the so called "low surface reactivity" plastics like PE most adhesives do not stick well. You can increase the adhesion very markedly by "flame treating" the surface prior to gluing.

If you already know this, ignore the following: it sounds like snake oil, but passing the ionizing part of a propane torch quickly over the surface increases the bond strength by many fold. The method is described on the West Epoxy site, basically you pass the part of the flame just beyond the blue cone over the surface very quickly - 10 or 15 inches a second, then bond within 30 minutes or so. You are not trying to melt the surface, it will not look different in any way. I was quite skeptical of the method and did my own tests using two different adhesives on Starboard, a HMPE which is considered to be unbondable. The result was a dramatic improvement in adhesion, with the failure within the glue itself rather than the surface bond.

Posted By: Jamm3r on 04/08/13 12:28pm

HMS Beagle wrote:

The tank itself is, I believe, ABS.

The bulkhead fittings and some of the repairs (go figure) are PE. I'm a big fan of flame treating, and used it on the PE portions. I used West Systems G/Flex for the bottom layer of the repair to the bulkhead fitting for the toilet. The G/flex is orange-brown and you can see it in the photo, while the regular epoxy is clear. G/flex is supposed to bond to PE better but I think that's mainly because it's more elastic and less prone to pull lose due to different rates of expansion during temperatures changes.

Posted By: 69 Avion on 04/08/13 02:39pm

I tried my tank when I repiped all the ABS piping (really bad workmanship with many joints having little or no glue on them) and I started having leaks. The first time I checked the tank, before the rebuild, I had no leaks. Upon close inspection, there were many hair line cracks. I gave up trying to save it and had a custom stainless steel 20 gallon tank made.

[image]

Picture of bad workmanship before and after:
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Ford F-350 4x4 Diesel
1988 Avion Triple Axle Trailer
1969 Avion C-11 Camper

Posted By: ticki2 on 04/08/13 03:08pm

Jamm3r wrote:

HMS Beagle wrote:

The tank itself is, I believe, ABS.

If your tank is truly ABS it can be repaired with ABS cement . However , I think you will find is is a form of PE , at least mine is . The only success I had with some cracks around the top fittings was with plastic welding . I also put ss band clamps around the fittings to reinforce them . The parts that screw into the fittings are pipe thread and tend to split the tank fitting if screwed in too tight.

Posted By: 69 Avion on 04/08/13 06:32pm

I agree with ticki2. I don't think that the tank is ABS. If it was ABS I don't think it would have cracked like mine did.

Posted By: Jamm3r on 04/09/13 09:31pm

Well, who knows. Mine has PE fittings, but I don't think the tank is PE.

In any case, epoxy sticks to it.

Here are my repairs before adding the flange. I used the non-woven fiberglass matting with West Systems epoxy. I have since figured out that Jamestown Distributors has a house brand epoxy that is quite a bit cheaper and would use that instead if I had it to do over again. It's not like I'm building a racing boat. I applied the matting, and wetted it out and added one more coat of epoxy and then sanded with an orbital pad sander and 80 grit.

[image]

I also sealed the insides of the cracks and relief holes with epoxy and placed enough near the flange in a pool to bring up the level of the bottom of the tank to be the same as the bottom of the flange.

Then I applied a Valterra flange. There's plenty of other stuff that would work but these are readily available. I had to enlarge the hole on the tank slightly with a drum sander to allow the inner lip of the flange to fit. I applied epoxy to both surfaces and held the flange down with a weight, then applied more fiberglass mat over the flange. I chose a hub-type flange so that I can fiberglass over the outside of the hub for more strength.

The clamps help hold the mat in place.

[image]

I've since removed the clamps and added another layer of epoxy.

The important thing here is to distribute the load widely enough to avoid any more cracking.

The new valve will be slightly shorter and I think I'll try to line up the control shaft at the top of the little recess so I can put the greywater control (which is cable operated) below it.
[image]

Posted By: Jamm3r on 04/09/13 09:35pm

69 Avion wrote:

I tried my tank when I repiped all the ABS piping (really bad workmanship with many joints having little or no glue on them) and I started having leaks.

I think you've posted extensively on the problems with the drain piping, and it was a problem area on mine as well, although I only had a couple of joints that leaked. I repiped everything just as you have.

Quote:

The first time I checked the tank, before the rebuild, I had no leaks. Upon close inspection, there were many hair line cracks. I gave up trying to save it and had a custom stainless steel 20 gallon tank made.

How much did the custom tank cost?

I'm mainly trying to save a buck or two here. I was using the epoxy mainly for the plastic pieces inside the bathroom so I'm only out around $50 in additional materials, including the new valve.

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