12 foot PVC boat project

[dynamic37]

Hello.

I have a 12 foot inflatable boat that needs attention. One repair srecialist adviced me to throw it away, another told me to go for it. So I am on need of feedback from nomeone who have experience.
Economywise I think it is worth it as I was given the boat for free.

Transom:

The first thing I had to do was to manufacture a new transom as the old had a big crack in it. I have almost finished this job.I made the new transom using plywood (not marin grade). I had to laminate two pieces as the old transom was very thick (46 mm). Next I will treat it with 3 layers of epoxy and finish off with a two component polyurethane boat paint. I the need to fix it to the boat. It is bolted to rubber guides, and the hull material is glued/screwed to the transom. A second piece of wood is fastened on the outside (so the hull material is ?laminated? between two pieces of wood).

New transom

Tubes:
The tubes are fine as far as I can tell. I have checked for leaks using soap water. There are no holes anuwhere. I had to replace the front valve (I was given the original valves from the manufacturer).
The problem here is to tighten the valve enough. It leaks, and I need to find a way to hold the back nut (inside the boat) as I tighten the valve itself. I am nearly there The back tubes are tight and fine. The keel tube (it is an inflatable keel) has 4 pinholes, but these are easily repaired.

Hull.
Now to the main problem: The hull material. The material is ftiff and has a lot of cracks in the surface. It also has a hole in it. The keel protector has fallen off along most of the keel, and there is a hole at the edge of the remaining front piece.

The hull PVC glue has also loosened a couple of places along the edge.

The plan for the boat is:
Finish the transom and fit it to the boat.

Reattach the hull material to the tubes on both sides of the transom (glue in place and add an extra patch to strengthen the area)

As far as the hull PVC goes, I have two options. Either replace it, or glue a new floor on top of the old. I think I will go for the last option. I will glue a new floor in two pieces (right and left) and glue a strip of PVC along the keel overlapping the two halves. The new floor will be glued to the tubes about 2-3inches wider then the old floor. I will also glue PVC to the bottom of the tubes to reinforce them.

I will use PVC material from HEYTEX and glue from Zodiac



Pictures of the boat

Any thoughts on the project?

 

[Drowned Rat]

Re: 12 foot PVC boat project

Well, it looks like there is more than one boat in the pictures you posted. I can't tell. Anyway, the one will yellow on it has sustained serious sun damage it looks like. I'd worry about it holding up under pressure. The grey boat, tubes, look fairly good though except for the isolated damage you point out. Gluing on the bottom shouldn't be a problem the way you describe it but it'll have to be a quality job to hold up. That transom looks great but it should've been made from marine grade plywood. Even with the expoxy paint, it's going to be very hard to keep water out of the wood fibers altogether. Any moisture in that at all and it's going to delaminate. Take extra time to make sure you seal it very well.

Have fun with it, post lots of pics!

 

[dynamic37]

Re: 12 foot PVC boat project

It is all the same boat. The first lipctre in the gallery is the most recent. Some of the ortehr where taken at night in the winter with a flash. It might look worse than it is in those pictures. But of course, it has faded.

 

[nobrainsd]

Re: 12 foot PVC boat project

I can see why some may have advised you to trash the boat. The time, effort and supplies required to get the boat back together are probably excessive for the value of the repaired boat. But if you have the desire, well, why not? I have seen many a river raft with large patches on the lower side of the tubes and all sorts of layered repairs. But I wouldn't go for gluing a new floor layer over the old floor. Even with more of an overlap on the sides, where the floor is glued to the tubes, you won't be getting any added strength from the glued strip on the interior. You do want to have both the outer and inner bond intact if you intend to use the boat for any strenuous water activity. I would remove the floor and reglue the inner and outer seams.

If you just want to have a useable boat and aren't trying to totally restore the vessel you might consider using a liquid rubber paint to coat, seal and reinforce your aging PVC material. http://www.allinflatables.com/shopping/paint/faqs.htmlI have seen small inflatables that have been coated with this rubber paint and it really does work. Sure it adds some weight, can make additional repairs more difficult and is virtually impossible to remove, but these rubber coatings can definitely extend the life of inflatables that are nearing the end of their useful lifespan. The individual whom I discussed this product with had reglued some of his transom and floor seams, patched a couple of places and then coated the rest of his boat. He said there were too many areas where the PVC was abraded or cracking to address them individually so that was why he painted the boat. It had held up for a couple of years already, but he recognized that the next stop for the boat was the dump.

You might want to skim through the following thread about transom repair. http://forums.iboats.com/showthread.php?t=266962&highlight=nobrainsd Good luck!

 

[dynamic37]

Re: 12 foot PVC boat project

This paint is impossible to get here in Norway, as well as the "liquid rubber" made by Inland Marine.

It seems like the bottom material as it is now still holds the boat together fine. By adding a second floor, I will keep the water from deteriorating it further

 

[kandil]

Re: 12 foot PVC boat project

It looks good you can do it you should try and glass the transom instead of painting it good luck

 

[dynamic37]

Re: 12 foot PVC boat project

You mean using fiberglass cloth together with the epoxy?

The paint I am using is very hard two component (like lacquer) made for boats.
So if I understand you right, I first saturate the wood with epoxy, then use epoxy and cloth and last I paint?

The plywood I have used was the best I could find in that thickness. It seems very sturdy and dense.

 

[Dag Deberitz]

Re: 12 foot PVC boat project

As I told you on the phone Asbjoern, - I think you should go for your plan!

I would, - however, - recommend you to make another transom of water resistant red plywood and laminate 2 or 3 pieces together with for example Tec7 under pressure by carpenter's pliers to obtain right thickness and longer durability of it. I did that to replace my 1988 Zodiac Futura MKIII transom and I didn't regret that.

And remeber to allways keep the right air pressure in the pontoons. Useing too low pressure is the worst enemy to dingys and RIB's! That's my best advice after haveing repaired such boats for more than 23 years

Best wishes from Dag Deberitz, Stavern, Norway

 

[dynamic37]

Re: 12 foot PVC boat project

Fixed the valve. Pumped up the boat hard and turned the outside of the valve until it suddenly stopped. It seems the air pressure held the inside nut in place. Now it is tight. No air escaping anywhere