rivet size help needed

[seanymph85]

I have a 1985 Sea Nymph 14R Big water aluminum v-hull style boat. Some one at one time or another had some leaks and put a bunch of spray on sealant on the outside of some seams on the boat and silicone sealant on some areas of the inside of the boat.

In the area I was trying to check the rivet size there was also sealant in between those rivets. I tried measuring the reach I will need for the rivet but in trying to measure I am getting slightly different readings with the caliper from 1/64 under 1/4" to slightly over 1/4".

In any case it is difficult to say with extreme accuracy what the total reach of the new rivet should be. It could be slightly under to slightly over 1/4" in reach. Does anyone know what is common or typical reach for the rivets on this boat? Would all of them on the seam areas in front and rear of the boat likely be the same diameter and reach? I do have a 3/16 diameter rivet that likely has to long a reach but I could perhaps put it in the hole and try to measure how much of it sticks out and subtract that from the total length of the part that goes through the hole.

I am probably over thinking this as with other things but want to make certain I get the correct reach so the end result will be as tight a joint as possible. Also on rivet hole was somewhat dimpled. I need to know if I need to do anything different there with the rivet to insure the part of the rivet on the inside of the boat will pull in correctly and be sealed well.

 

[jigngrub]

You should be fine with a closed end blind rivet with a grip range of .126-.250"

 

[seanymph85]

Thanks for the info. I will order some from Jaycees rivets online. They are only a few hours at most from my location here in South West Michigan. I have also noticed that some suggest 3M 5200 and or Gluvit sealant when installing rivets. I believe one needs to be painted over afterwards. Do you have a preference for either one?

Further it is hard for me to understand how these rivets can leak and still be so hard to knock out after removing the head. I am beginning to wonder if it isn't leaking between the seams and not around the rivet itself. I figured if they were loose they would be easy to pop out after removing the head but so far it is simply separating the two layers of metal and mal-forming the surfaces somewhat in the process.

One hole is dimpled in somewhat And I wondered if I would need to add a washer or something to the inside of the boat where the surface is dimpled in when the rivet was knocked out.

There is so much sealant that needs removed that without removing most or all of the bow trim rivets to loosen the trim enough from the inner metal I am uncertain how I can get it all cleaned out and be certain the two layers of metal will draw together as tight as possible when the rivets are replaced unless I do just that. Still I don't think you are supposed to remove that many rivets at one time, but then I am of course no expert on this.

Thanks again for any input or suggestions you can offer. In the mean time I will order those rivets.

 

[jigngrub]

My first choice is a good marine epoxy like Loc-tite marine epoxy for installing rivets and 3M 5200 is a close second. Gluvit goes on the inside of the hull after all the leaking rivets are fixed, pay special attention to the seams with the gluvit.

Your seams may be leaking and gluvit on the inside will help fix that.

Don't worry about a washer on the dimpled rivet hole, just give it a healthy dose of epoxy or 5200 when installing the rivet.

Don't worry about removing rivets to clean off the sealant crapola, just clean it off the best you can by hand and then use a wire cup brush in a grinder if you need to. Chances are that the amount of sealant in the seams is minimal and one of the reasons your boat was/is still leaking.

 

[seanymph85]

It's ironic but I was just checking out that Loctite Marine epoxy and saw Wal-Mart should have it. Only thing is, there are a good number of rivets leaking or appear to be leakingin the bow area so I am uncertain but I may need a fair amount of epoxy. Any idea about the working time on the Loctite Marine epoxy? Can anything be put on the outside seem if needed? Course if the inside is well sealed that should help take care of things too.

So the gluvit goes on both the rivets and the seams on the inside, is that correct? Is it fairly thick? There is a recessed cavity in the bow of the boat where it may take working the gluvit into the seam. That is why I ask about the thickness. I will try to add a picture to show what I am referring to soon. I will look for some of the Gluvit online.

Thanks!

 

[seanymph85]

No Title

 

[jigngrub]

The Loc-tite come in a few pot life mixes, the common ones are the 5 minute and the 2 hour mixes.

Gluvit is very runny/drippy for penetrating tight cracks, and that's why it's used on the inside of the hull so gravity can pull it down into the cracks/nooks/crannies of the seams and rivets.

Trying to repair leaks on the outside of an aluminum boat with goo and sealant is a waste of time, the best results you can hope for will be temporary, if it even works at all. You can fix leaks from the outside by replacing rivets and applying patches, but that's about it... everything else needs to be done from the inside.

 

[seanymph85]

Okay thanks, I will try to find something to clean off the old sealant on the outside of the boat. If nothing else for somewhat better appearance. I can put the Gluvit on the inside and let it run down into the seams of that recessed area. They had also put large amounts of silicone sealant in that recessed cavity but I believe I have that fairly well cleaned out. There is heavy oxidation on the outside of the bow too. I am not interested in polishing the metal just cleaning it up.

Thanks again for the tips. I have ordered the rivets from Jaycee's and will proceed accordingly on the inside with Gluvit. Will try to post back at a later time with info on how the leak repairs have turned out.