RIB repair. Hypalon and ?

[skipmac]

Originally Posted by Jim Cate

fwiw, UV resistance is not of much concern in this sort of repair. The entire glue join area is behind the thick rubbing strake and is not exposed to UV.

What is crucial is the bond strength, especially if the dinghy is deflated and rolled or otherwise compacted. It is t he stress caused by the small radius bends in the strake that typically breaks down the bond.

Jim

I would concur with all the above. In addition to bond strength I'm also looking at the flexibility of the adhesive which is advertised as a property for several of those that have been mentioned.

[skipmac]

OK, after four pages of posts the answer is clear as mud.

Actually, a lot of good information and I think several possible options. Here's my summary of what I see so far. Please add, subtract, comment or add suggestions to this list.

1. Hypalon Adhesive. PolyOne, Weaver, 3M, Bostik and a couple of others.

Pros
- Formulated for Hypalon and have excellent adhesion
- Flexible
- Easy application, essentially contact adhesives so no clamping or holding in place for along cure time.

Cons
- Will not stick to PVC or in general any other polymer like PE, PP but Weaver tech support offers a solution. Use their PVC adhesive first on the PVC components then coat Hypalon adhesive on top of that to bond to the dinghy tubes.
- Expensive
- Shelf life. Make sure to get fresh product.

2. 5200

Pros
- Inexpensive
- Available locally
- Differing opinions on whether or not it will hold and last. I tend to think it would work very well.

Cons
- Application requires clamping or some way to hold the parts in place for a long cure time
- Messy to apply. Mask everything in reach.
- Once it's on, it's on. Screw up the job and you will have to live with it.

3. Marine Goop

Pros
- Inexpensive
- Claims to work on polymers as well as Hypalon
- Data sheet shows several solvents that should dissolve the bond so if you make a mistake it isn't permanent.

Cons
- New product so less of a track record.

4. MarineTex Flex Flex Set

Pros
- This product is new to me but MarineTex is a brand I know and like very well.
- Flexible
- Easy prep. Only need to remove any loose, peeling or soft spots of the old adhesive. Any areas where the old adhesive is hard, dry and well bonded to the Hypalon are OK as is.
- Claimed to bond well to Hypalon, PVC, PE or PP (PE or PP require a heat treating step).

Cons
- Expensive
- Not sure if it is removable.
- There is some bonding time the requires holding the parts together but minimal.

[Capt Gill]

There's a common first step, required for all the adhesives, that needs to be strongly emphasised :
Proper preparation as per instructions.
After many hours of unspeakable torture I confess this to you. You are now warned!

[pitlaw]

So I was inspired by this thread to tackle my Avon pvc and reglue its rubrail. But Toulene doesnt seem to help much in removing the glue. In fact its one heck of a frustrating job. Any glue removal suggestions for pvc inflateable Avon 310?

[skipmac]

Originally Posted by pitlaw

So I was inspired by this thread to tackle my Avon pvc and reglue its rubrail. But Toulene doesnt seem to help much in removing the glue. In fact its one heck of a frustrating job. Any glue removal suggestions for pvc inflateable Avon 310?

Oh no. I've created a monster. My apologies.

I haven't tried toluene but tried acetone and it didn't touch the glue at all. Based on discussions with a couple of the tech guys at the glue manufacturers I'm leaning towards abrasive instead of solvent. I did a couple of test batches that went fairly well but did the test by hand. Would probably work better with your favorite flavor of power sander but be very, very careful not to sand down so far you can see the air inside the dinghy. Actually I think you shouldn't even get beyond the rubbery outer layer to see the fabric.

Good luck.

[skipmac]

Originally Posted by Capt Gill

There's a common first step, required for all the adhesives, that needs to be strongly emphasised :
Proper preparation as per instructions.
After many hours of unspeakable torture I confess this to you. You are now warned!

After a couple of test patches I'm already dreading the preparation. That is a lesson I learned long ago (unfortunately I learned it a couple of times), good prep saves work in the long run.

[skipmac]

Mr Google taught me a neat trick. How to tell if a piece of something is PVC or some other polymer. It's called the Beilstein Test. It shows PVC by detecting chlorine but will also show the presence of other halides.

CAUTION!!!!

From Wikipedia. This test is no longer frequently used. One reason why it is not widely used is that it is possible to generate the highly toxic chloro-dioxins if the test material is a polychloroarene

It determines the presence of PVC by detecting the presence of chlorine. You need a propane torch (or bunsen burner) and a copper wire. Copper wire by itself burns cleanly but when combined with a material containing chlorine (PVC) it burns green. Heat up a copper wire over a flame (use pliers to protect yourself and use a long wire) to remove unwanted residue. Press the hot wire against your plastic sample so that some of it melts onto the wire then replace the plastic covered wire onto the flame and look out for bright green. If it burns bright green you have PVC.

Finally, PE burns with smell like burning wax while PVC has a very pungent chemical smell and extinguishes itself immediately once taken off a flame.

[JPA Cate]

From your summary, I'd be very tempted to try the Marine Tex Flex Set, because it claims to bond well to both types of surfaces, the hypalon and the PVC.

As to method, Jim has abraded the old glue off, then cleaned the surfaces with acetone or toluene. However, if you use the Flex Set, follow their cleaning instructions over mine.

Ann

[Scout 30]

Originally Posted by pitlaw

So I was inspired by this thread to tackle my Avon pvc and reglue its rubrail. But Toulene doesnt seem to help much in removing the glue. In fact its one heck of a frustrating job. Any glue removal suggestions for pvc inflateable Avon 310?

I'm pretty sure that all Avons are hypalon, not pvc, although I'm not sure what the rubrail is made of. It does appear to be too flexible for pvc but I'm no expert. I'm thinking about thru-bolting my rubrail on. All these different adhesives are giving me a headache.

[skipmac]

Originally Posted by Scout 30

I'm pretty sure that all Avons are hypalon, not pvc, although I'm not sure what the rubrail is made of. It does appear to be too flexible for pvc but I'm no expert. I'm thinking about thru-bolting my rubrail on. All these different adhesives are giving me a headache.

I've had a headache since I started researching this little project.

I have learned that PVC can be made quite flexible by the addition of a plasticizer like DOP or DINP so flexibility is not a way to determine what the rail is made of.

Through bolting sounds good but if you're in a hurry just use self tapping screws.

[Capt Gill]

"All these different adhesives are giving me a headache." Instructions state:use in well ventilated area. I would add,"use and read".

[skipmac]

Wow, science works!

So decided to give the Marine Tex Flex Set a try for the job but needed to verify the material used for the rail, as PE or PP require a different procedure than PVC. I suspected the rail is PVC based on previous investigations but needed to know for sure. So I tried the Beilstein test.

Got a piece of copper wire about 6-8 gauge, heated it red hot with a propane torch, rubbed it on a cleaned spot on the back of the rail to melt a bit of the plastic onto the wire. Back into the propane flame and voila, a bright green plume came off the wire from the PVC residue. Very cool.

I did do this outside with the fumes well away from me and downwind so probably retained most of my remaining brain cells.

[Scout 30]

Originally Posted by skipmac

Wow, science works!

So decided to give the Marine Tex Flex Set a try for the job but needed to verify the material used for the rail, as PE or PP require a different procedure than PVC. I suspected the rail is PVC based on previous investigations but needed to know for sure. So I tried the Beilstein test.

Got a piece of copper wire about 6-8 gauge, heated it red hot with a propane torch, rubbed it on a cleaned spot on the back of the rail to melt a bit of the plastic onto the wire. Back into the propane flame and voila, a bright green plume came off the wire from the PVC residue. Very cool.

I did do this outside with the fumes well away from me and downwind so probably retained most of my remaining brain cells.

This is why I love this forum!

[Scout 30]

Originally Posted by skipmac

Wow, science works!

So decided to give the Marine Tex Flex Set a try for the job but needed to verify the material used for the rail, as PE or PP require a different procedure than PVC. I suspected the rail is PVC based on previous investigations but needed to know for sure. So I tried the Beilstein test.

Got a piece of copper wire about 6-8 gauge, heated it red hot with a propane torch, rubbed it on a cleaned spot on the back of the rail to melt a bit of the plastic onto the wire. Back into the propane flame and voila, a bright green plume came off the wire from the PVC residue. Very cool.

I did do this outside with the fumes well away from me and downwind so probably retained most of my remaining brain cells.

Very interested to know how the repair goes & how much adhesive you needed.

[skipmac]

Originally Posted by Scout 30

Very interested to know how the repair goes & how much adhesive you needed.

Will definitely post results when done.

As far as how much it will take, even the engineer at Marine Tex couldn't say how much area a single kit would cover so I just gave it a WAG and order 4 X 30 gm (about 1 oz) kits.