leak inside a seam of a 2005 boat

hope this isn’t redundant, but i haven’t found info about this specific issue.

i’ve identified 6 tiny leaks on a raft purchased back in 2005 (it’s yak-sized, not sure if they were called that back then)
they are all on the outside bottom where the yellow seam tape meets the black bottom.
before plowing ahead with a repair, i wanted to give a shout out and ask for technique tips.
can anyone give their feelings/experience on dot of aquaseal vs. patch n go patch with aquaseal around the edges? it’s just a little bit funny because they’re in a funky little corner seam and not the middle of the tube. it seems like the actual hole is somewhere inside the seam and the air is just making its way out at the corner.

also, auto mechanic buddies want to get their hands on it and fix it like they would a tire. terrible idea! right?

many thanks


Perhaps have a look at the thread I started in ‘General Discussion’ on Inflatable Boat/Raft Sealant!

I had this exact same problem in a circa 2004 boat in 8 of the seams on the bottom. I just smeared aquaseal all over each of the junctions and called it good. So I don’t really have a basis for comparison but it seems to be working fine.

I have the same problem in my 2004 Alpaca. It appears as if there are one or more leaks in the tube seams where they connect to the floor. As a result, anyplace the floor has a ridge, like near the tube seams, it will leak. The leak(s) between the tube and floor bubbled out both on the inside floor seam and the outside floor seam. I glued (Aqua Seal) along the perimeter of the complete outside floor bottom and the stern area on the inside. The boat still looses a little air someplace but much less now.

I would like to hear from Alpacka as to what caused these types of leaks in this era boat?

Hi Guys,

It is Sheri chiming in on this one. Yes, we have had occasional leaks show up on the 03 and 04 models under the floor. If your boat has yellow tape it is either an 03 or an 04 model. Those are the only two years with the yellow tape. That issue did resolve itself with the black tape. The cause takes way too long to explain, and it was one of those things you don’t find until a couple of years down the road.

Fortunately there is a very good fix for this problem. We are happy to do it for you or you can tackle it yourself. The hardest part of doing it yourself is first getting a hold of some Clifton one part adhesive or Stabond adhesive. These are both contact glues for urethane. These two glues are my first choice to do the finishing of the repair. You can make patch n go work just fine, but for a permanent repair of the size you will end up making I prefer to go ahead and put a fabric patch on. The next hard part, and this seems to gag everyone, is you have to cut into your boat. it is like stabbing your dog for most people. But fear not, it repairs easily and it is the only way to get to the root of the leak problem.

First find exactly where your leak is coming from and mark the tube above this spot.
Next make a vertical cut in the tube above this leak. I usually go for the inside of the tube so it isn’t so visible. The cut should be about 4 inches long. Don’t too near the floor either, it will make it more difficult to close this hole properly.

Now that you have the inside of the tube exposed match up where you marked the leak on the outside with what you see on the inside. Wipe this area with alcohol and put a good sized bunch of aquaseal over it. Let the aquaseal cover at least two inches more than what you are seeing as the leak area. You are covering the actual main seam here.

Let the aquaseal dry overnight.

The next day take patch n go and close off the inside edge of the cut in the tube. Take a look at my repair video on the site to see how to do this step.
Then you can put patch n go over the outside of the cut or you can get a scrap of fabric from us and use the contact adhesive that I mentioned earlier to apply a patch. With both the patch n go and the fabric patch make sure your patch is at least 1 1/2 inches wider than the cut line on all sides.

You cannot repair this problem from the outside. The air will just leak around your sealing attempt. You must get to the inside of the tube. But, if you do swallow hard and rip into the boat and repair it from the inside the boat will be 100% again.

Or you can just send it down and we will fix it for you. Also, if you guys are in Anchorage I can give Eric Parsons a good tutorial on how to fix it and you can give him a shout. He does really good repair work.

Good Luck,

Note: for those newer to the community, Sheri is our inventor. Cheers, -Alpacka

Yup, I’ve got the yellow tape. That repair does sound fairly scary though. Maybe I’ll wait until I’m back in the States and see if Shaggy can help me fix it. :slight_smile:

You got it straight Sheri, the hardest part of doing it yourself is first getting a hold of some Clifton one part adhesive or Stabond adhesive. Both are definatly not available in Europe. :frowning:

I have an unglued Dory Deck and 12 Tieloop ready to take on for months, but all I am coming along are dodgy answers from shops, manufactures and cutomer services.

I learned, Clifon contains Tetrahydrofuran (THF) as dissolver. I that the key thing? I found THF available in its pure form,
but it is acutually more associated with cold welding of PVC (like swimming pools etc).

I also found glue made of PU, but free of any dissolver (UHU PU Max), but I think, this will stick, but not bond to PU, right? Also, it is slightly foaming while drying.

How about mixing those two - the THF with the PU glue? Would that work to dissolve the urethan surface and at the same time provide a film of PU inbetween?

Most other manufactures recomment to test their 1-K PU contact glue (they are not saying it the same as Cliftons, as those dont provide incredients), but I dont have spare material to test … (http://www.pattex.de/Pattex-Kraftkleber-Transparent.1490.0.html) Recommended for PVC in the first place, but Andrew said I should avoid PVC adhesives.

I am quite confused and dont want to mess up 1000 $ Boats … I tried to get a hold of Andrew about that, but he seems to be in the outdoors.

Hope you 'll read this post.

Many thanks, Sven

Hi Sven, I’ve got your e-mail, I’ve just been snowed for the last couple days - and Sheri’s the one in outdoors right now. :smiley: I wanted to wait until I could ask her about it.

Hi Sven,

I just got off the river. Here are some recommends for you.

First, do NOT put the straight THF on your boat!!! It will dissolve the urathane coating totally. It turns it to liquid in approx 2 seconds and you will be staring at your fabric with no coating on it.

I don’t know about mixing the two glues. If you did try it I would put a very tiny amount of the THF in.

On the PVC glue, Andrew is right in general you don’t want PVC glue because it won’t glue urethane. However there are some cross over glues and they work fine. These glues will say they adhere to Urethane as well as PVC. If the glue does not specifically say it will glue urethane, then it won’t. Both clifton and stabond are cross over glues. They will glue both urethane and pvc.

What I would recommend for you Sven is to try the glue you are talking about on your boat. use a very small test circle under you seat on the tubes right near the floor. That is a spot you will never see. You won’t damage the urethane if the glue doesn’t work because it will just peel right off again. And if it doesn’t peel off then you know it is adhering which is what you want. Better yet you have all those grabloops I mailed you. Just use the underside of the grabloops to test your glue. If it works on the grabloop then it will work on the boat.

If the glues don’t work why don’t you have me mail you some narrow strips of the patch n go and you can adhere you deck on with it. It won’t be perfect but it will work OK.

On the grabloops you can make them work with aquaseal. Again, they won’t be perfect, but they will pass. wipe both the boat and the grabloop down with alcohol. Then spread a very thin layer of aquaseal on both the grabloop and the circle you have drawn on the boat where you want the grabloop to go. Let these dry for about 6 hours. The glue should feel pretty dry to the touch. Then stick the two together. You only get one shot, the glue will really stick to itself. To really secure it you will want to put a small bead of aquaseal around the outside edge of the grabloop after you have stuck it to the boat. This bead should be on both the grabloop and the boat itself. Make sure you wipe it with alcohol first.

I have a few more ideas if none of these work so keep me posted.

Cheers, Sheri

Welcome back Sheri and thanks for the advise.

I have now come by with 3 (4 with Aquasure) different “PU contact glues” out of 6 contacted manufactures. None of them specifically mention urethan, only rubber, PVC, Wood etc. If I ask, they dont let them get nailed (responibility). If I refer to Clifton, they ask for the composition, but Clifton doesnt provide the recipie :wink: So, we dont know what the key thing is chemically wise.

Anyways, of those 3 are 2 dissolver containing and 1 dissolver free glue. I will see. I only wish I could make a proper testing on spare material and have a stress test. Best result I would recommend for other Europeans :wink: I would sacrifise some Tieloops for now :frowning: However, mail me some (spare mat) if you have.

Thanks for the Idea with patchngo for the deck. I came up with that too, at least for clean sealing the edges of the deck, as I dont have the black stripes I noticed on the edges of the deck of my Llama. However, I would have not imagined this would strong enough.

How many rolls of pachngo would need?


P.s. on a side note, a big vote for brightish color in 2010, my Girlfriend doesnt suit army green :wink:

Hi Sven,

I will happily mail you some sample fabric. On the patch n go I would recommend getting just the tape, not the kit. We sell it by the foot or yard. You will cut it in half lengthwise so you need enough length to go around half of the spraydeck. I will measure it when I am in the shop on Monday but I think you will want 2 yards. That patch n go is pretty strong and if you are good to your spraydeck and don’t jerk on it or pick the boat up by the spraydeck it should work OK.

Email me at sheri@alpackaraft.com and I will give you the totals of what you will need of the patch n go.

Cheers, sheri