Inside patching of tubes

DanAzWa · 19 May 2025, 22:51

So I am getting ready to do my first Hypalon patch. It's on the back of a tube.
One of the layers on the curved part started pealing off. The actual space that needs repair is approx 75mm x 75 mm.
I've studied patching extensively and got the correct glue, but have never patched much, other than a bicycle tube.
I actually think my lack of experience allowed a small leak to tear into a larger one. Due to the high surface water friction in this area, I plan to put a patch inside and then either glue the existing layer back down. Or cut it off and replace it.
My question is, how to get into that small of a space to sand and glue.
Seems nearly impossible. In addition to getting the internal patch properly placed.
Should I open the hole further, or skip the inside repair and just work from the outside?

Dry Run · 20 May 2025, 07:07

I know people like to try and repair things themselves, but sometimes that can be false economy. Here in the UK a job like that from a professional tube repairer would probably be about £100 - don't know about stateside?

User name · 20 May 2025, 12:36

Quote:

Originally Posted by DanAzWa

So I am getting ready to do my first Hypalon patch. It's on the back of a tube.
One of the layers on the curved part started pealing off. The actual space that needs repair is approx 75mm x 75 mm.
I've studied patching extensively and got the correct glue, but have never patched much, other than a bicycle tube.
I actually think my lack of experience allowed a small leak to tear into a larger one. Due to the high surface water friction in this area, I plan to put a patch inside and then either glue the existing layer back down. Or cut it off and replace it.
My question is, how to get into that small of a space to sand and glue.
Seems nearly impossible. In addition to getting the internal patch properly placed.
Should I open the hole further, or skip the inside repair and just work from the outside?

75mm square is a decent size to work with for an internal patch. If you let the tube lay flat (might need to deflate neighbouring tube) then you should be able to fold the fabric at the hole and you'll be able to prep it with 2 or 3 fingers. You should also have no probs getting a small brush in there. Don't worry about keeping the glue line tidy on an internal patch. Go a little wider than your patch, just so you can be sure you're not leaving a loose edge.

When it comes to positioning the patch, I like to measure up and cut a patch on the outside, leaving enough overhang and then draw a dotted crosshair on it with a marker. You can then size it up and leave corresponding marks on the outside of the tube to line the crosshair up with. This way it makes it a lot easier for you to know you've placed the patch exactly where you wanted it, even though you can't see the edges. If your damage is near any of the valves, you might be able to remove one and use the hole to help you work on the patched area too.

If you've done all the glue prep steps then by the time it comes to applying the patch, the glue will be near dried on the surface so it won't be too grabby when you're pushing the patch through the hole. Once in position, you apply pressure (as much as you can. A roller, rubber mallet etc) and this what will really bond the patch to the tube.

A few pics would help to understand your exact problem, but you might get away with just regluing the external part once you have an internal patch in place. It would always be better to have an external patch instead of re-gluing any damaged fabric, though it's hard to say without getting a better understanding of the damage you're working with.

DanAzWa · 20 May 2025, 20:52

Thank you both for your input. I'll report back any strange lessons I might learn.

Peter_C · 21 May 2025, 21:09

A picture would help, but two would be better. One close up and another standing back a little bit. Not seeing means I am not sure an inside patch is necessary.

DanAzWa · 22 May 2025, 02:59

First problem is somebody before me saw fit to paint things with some blue paint that has turned chalky and is coming off. Obviously, I'll have to remove as much as necessary of that to get a good idea of what I'm working with, hopefully acetone will cut it enough that I can get it off with a stiff brushing.

The split seam is on the bottom right of the back of the tube, which is why the tube is so distorted. Had to lift it and tie it back to have work space for the leak.

The seam that is open is one of two rings (picture 1) of hypalon that go around the back end of the tube. The actual air leak is in the corner where the seam meets the one that goes perpendicular to it (top right corner of photo 4). I think I'll have to remove some material (picture 2) before I start trying to repair, but won't try to make that decision until I see how much of the chalky blue stuff comes off.

I'm also concerned that I'm looking at material delamination (picture 3 & 4). Although I can't yet tell if it's the tape they used to make the rings, or the actual base material.

I hope this makes sense. And I'm willing to post more pics if it helps get a better picture of what I'm facing.

Peter_C · 22 May 2025, 06:06

What year is the boat? Has it lived it's whole life out in the sun?

What is the bottom of the boats color? What is the original color?

Just trying to figure out what that grey stuff over the black is?? If that is the first layer of hypalon the tubes are toast. Just looking at the old age yellow color of the seam coming apart doesn't look good. How about a whole boat picture and one of the bottom of the boat please?

New tubes are very expensive and few places make tubes. The material is very expensive.

DanAzWa · 22 May 2025, 18:06

Boat is a 2002. I don't know any of the history beyond 3 months ago.
The boat is a mid grey color, but the ends of the tubes have been painted over with different layers of grey and/or blue, (so it's hard to tell what layer is what color). At least that's what I believe is flaking off. I've never seen hypalon in progressive states of decomposition so I don't have any reference.

I definitely won't be retubing this boat. This was to be my intro RIB before I went a bit longer, and more expensive. I am, however; thinking of trying out a product called "Inflatasaver" just to get a little more mileage out of it.

I really appreciate your input. I'll shoot some full pics later today and post up.

jonp · 22 May 2025, 22:45

Quote:

Originally Posted by DanAzWa

First problem is somebody before me saw fit to paint things with some blue paint that has turned chalky and is coming off. Obviously, I'll have to remove as much as necessary of that to get a good idea of what I'm working with, hopefully acetone will cut it enough that I can get it off with a stiff brushing.

The split seam is on the bottom right of the back of the tube, which is why the tube is so distorted. Had to lift it and tie it back to have work space for the leak.

The seam that is open is one of two rings (picture 1) of hypalon that go around the back end of the tube. The actual air leak is in the corner where the seam meets the one that goes perpendicular to it (top right corner of photo 4). I think I'll have to remove some material (picture 2) before I start trying to repair, but won't try to make that decision until I see how much of the chalky blue stuff comes off.

I'm also concerned that I'm looking at material delamination (picture 3 & 4). Although I can't yet tell if it's the tape they used to make the rings, or the actual base material.

I hope this makes sense. And I'm willing to post more pics if it helps get a better picture of what I'm facing.

Those tube would not give me confidence offshore in bad weather, they look old and ready to be replaced. Personally I would be finding an expert in making tubes to get their opinion, not just on that repair but the condition of the full tube set.

User name · 23 May 2025, 11:36

Quote:

Originally Posted by DanAzWa

First problem is somebody before me saw fit to paint things with some blue paint that has turned chalky and is coming off. Obviously, I'll have to remove as much as necessary of that to get a good idea of what I'm working with, hopefully acetone will cut it enough that I can get it off with a stiff brushing.

The split seam is on the bottom right of the back of the tube, which is why the tube is so distorted. Had to lift it and tie it back to have work space for the leak.

The seam that is open is one of two rings (picture 1) of hypalon that go around the back end of the tube. The actual air leak is in the corner where the seam meets the one that goes perpendicular to it (top right corner of photo 4). I think I'll have to remove some material (picture 2) before I start trying to repair, but won't try to make that decision until I see how much of the chalky blue stuff comes off.

I'm also concerned that I'm looking at material delamination (picture 3 & 4). Although I can't yet tell if it's the tape they used to make the rings, or the actual base material.

I hope this makes sense. And I'm willing to post more pics if it helps get a better picture of what I'm facing.

That does look in quite poor condition tbh. It looks like the layers are separating in the fabric. If retubing it isn't an option, I'd say the next best way to repair it would be to make a new hole on the other side of the tube if the material is in better condition there. This will allow you to do an oversized patch on the inside of the damaged area and give you better material to work with when patching up the new hole you'll make. The external condition of this existing leak doesn't look like it'll take a patch very well at all.

spartacus · 23 May 2025, 21:39

Those tubes look done. Before you go anywhere with glue you need to flapwheel the area with an abrasive and get rid of the paint. If the tube material looks to be delaminating, then it’s game over. Any repair will be a compromise.

DanAzWa · 24 May 2025, 05:13

Going to get a pro to look at it Monday.
It will help me to get a live set of eyes on it.

Peter_C · 25 May 2025, 18:09

[QUOTE=DanAzWa;883377]The boat is a mid grey color, but the ends of the tubes have been painted over with different layers of grey and/or blue, (so it's hard to tell what layer is what color).QUOTE]If the boat is not originally black, the tubes are done for.

Did the boat come with a trailer? Outboard?

DanAzWa · 27 May 2025, 04:14

Yes, both.