Okay fellow rafters, I posted awhile ago about wanting to rubberize or fix the bottom of my rafts. In particular, my Maravia (which is old) had so many pinhole leaks in the floor that it would not hold for 2 hours, but I still couldn't see them very well. The Tubes has a number of holes as well. Not as bad, but I'd still need to top off mid-day, and that sucks.
I saw the suggestions and the "Brush-On Wearpads" sounded like the thing to do. Pretty expensive, but it's only money. Manofrubber sold the 1lb. cans for $50 and the primer for $20. The rubber claimed to go about 6-8 sq. ft. and the primer 8-10 square feet. I ordered 12 lbs of the rubber and 10 of the primer. Doint the math, I spent a lot. When it arrived, I found that it was a product called Flexane FL-80 and the primer was Flexane FL-20. So I did some google search to see where else it could be purchased, etc. I found it at a place called weldwarehouse.com and it came in 3 sizes. The 1 lb was $36, the 4lb. was $111 and the 10lb was around $222. Quite a huge difference. I returned the stuff I purchased to Man of Rubber and paid a 15% restocking fee. I had no problem with that, especially given the fact that I could get twice as much and still be $100 ahead in the process.
Okay, got two 10 lb. cans of the stuff and 18 of the primer. The primer will go a long way. If you do this, know that they must say 8-10 square feet of coverage thinking that you are on some surface different than the rafts. In fact, I found them to have more than50 sq. ft. of coverage, and having so much, I was very liberal with it. 4 cans will easily do 2 boats.
To prep the PVC Marvia, I gave it a wash of COTOL where there were tricky parts, otherwise I just used rubbing alcohol and wiped it all up. Then I sanded the area I would apply the stuff to to rough it up. One more alcohol bath and made sure there was no more debris on the bottom. I tried several different things with the primer and the absolute best is a sponge and dishwashing gloves. This has an orange tint, so it in pretty easy to see where you have been. It shows up especially well on PVC, which is good and bad. Anyway, sponge it all over. It goes pretty quick, smells pretty strong, but you'd expect that. It needs to dry for about 30 minutes.
The 10 lb can of FL-80 is a chore for several reasons. You will have about 10-20 minutes to work with this stuff until it is too thick to work with. The last bits will not go on smooth, and I'll point that out in the pics. There are two parts, you add them together and you mix. For the 10 lb cans, use a drill with a mixer that you don't mind throwing away. Don't go too fast or you will get bubbles in the mix. Before you do all this, plan out where you are going to go. Most improtant places first, then a backup plan in case you have any left. My first task was the bottom of the floor and the tubes. From what the coverage suggested, I figured that one 10 lb can should come close.
Mixing was done (use a spatula to make sure you get all the goop out of the can), and I had several putty knives and brushes ready to go. NOTE: Do not use a brush. This is not "brushable" stuff. I suppose it is, but it will go on too thick, take too long, and you will run through brushes like crazy. I didn't know that, so I brushed it on. The first 3 minutes were fast, it went on smooth, and I thought I'd have enough for the bottom easy. From 3-10 minutes, it got slow and bad. The first stuff ended up dripping and the last stuff was too thick. If you go with a 10 lb can, get a friend to help because it is too tough to do correctly for 1 person.
It became obvious that I would need both cans to complete just one boat. So I do the next, and it didn't quite finish them. Too thick in some places, ran in a few, etc. Now if this sounds like a disaster, it isn't. I wish I had known then what I know now, but it was worth it. The flor of my raft (not inflated during installation to keep bubbles from coming out) was reinflated after the stuff cured, and it held for over a month. Didn't lose a bit. I darn near thought this stuff had the ability to keep air from compressing in cold weather. It was that good. The surface was slick and hard. I will probably keep the rafts inflated year round because this stuff will make folding even tougher than your typical PVC boat. The tubes held much better as well. The areas that the flexane dripped look like poo. If it drips past your primer coverage, it will need to be removed because it just won't hold. You can sand it or grind it. I tried both. The best is to carefully use a knife to get rid of the "stringers" and then grind the edge. Even that may not be necessary. Where it is stuck, it is stuck!
But I wasn't done with all I wanted. I knew I didn't want 10 lb. stuff again. I ended up with two 4 lb cans figuring it would be much more manageable, and I wanted it cheaper than the 1 lb stuff. This is a good amount to get. If I ever need to do this again, it will be with the 4 lb cans. Good compromise of price and useability.
I had a few places on the Maravia I wanted to touch up. That is as easy as sanding, priming, and putting down new flexane over the old. My Avon had wearpads that were showing fabric. All I wanted to do was cover those and take one shot across the front thwart area of the bottom where I had had some problems.
The 4lb stuff came with a little "spreader" that was just a small plastic trowel. This is what you need to use. If you get the 10lb stuff, find a little plastic trowel. It went on easy, smooth, and fast. Part of this is undoubtedly due to the difference in material. The PVC boats always have little ripples, no matter how tight you have them inflated. At least my old Maravia did. The avon also had zero leaks, so it held well. It is possible the Maravia settled a little, and I did see some small bubles that were likely where I had pinhole leaks. I buffed and redid those areas.
Okay, on to the pics. It was with my cell phone, and the lighting isn't great, but hopefully it shows well enough....

This is the Avon. Nothing more than rubber down the tubes and one across the thwart area. Smooth and lovely.

This is the maravia. A couple of notes. This was done about a month earlier and you can see how shiny it is. Also, I didn't get the very front done, and you can see how orange the primer is.

This picture didn't come out great, but this is what happens when you don't hurry. It starts to get unworkable and you end up with lumpy looking areas. Still strong, still functional, but it just doesn't look as nice. Fortunately, it is on the bottom.

This is another area that had the same thing happen. At this point of installation, it is hell trying to get this stuff to spread. So don't get the 10lb can.

The light isn't good here, but it is an alternate look at the Maravia.

This shows how the stuff ran. I think this is mainly from using a brush at the begining of application when the stuff is pretty easy. The brush puts too much on. This happened after I had left, or I would have tried to stsop it. But, it's on the bottom, and messing with it, it is secure (VERY!).

This should scare you off.

This is how it ran down the sides. Took a lot of time to clean it up, and it is still not good. My goal was to just make sure that anything on the boat was secure, and while ugly, this stuff is now secure. A direct result of using a brush instead of a trowel.
Well, that's it people. The Maravia is on its last legs (or was), so it was just an experiment. It didn't come out pretty because I didn't know all that you now know, but man did it ever take care of every pinhole leak I had. And it gives you some great armor on your boat.
Ask anything you want. Here is what you need to remember...
1) Don't get the 10lb can unless you have at least one other friend, preferably 2.
2) Don't brush it on, use a small, plastic trowel
3) Plan ahead for what you will do if you have stuff left over, and get the improtant stuff first.
4) The primer goes a long, long way.
Also, the place I got the stuff from (the welding place from above) has truly terrible customer service. It is only via email. But they are cheap. The only reason to contact them is to find out where your order is, which will probably ship direct from the maker. The maker has the best customer service in the world. Call before you apply and ask anything. They will give you any help you need. They were great to work with.