Aluminum Rivet Questions Trimming and Rivet Tool

[Stimputello]

So I have an old 80/s 14' Starcraft I had recently bought and have been putting quite a bit of work into it as it was previously a duck hunting boat that had seen quite some abuse. The whole bottom of the boat was covered in flex seal as a quick fix for the hunting season I'm assuming. The boat had a handful of marine putty covered bolts and rivets that were leaking slightly when on the water so I took it upon myself to drill them all out, clean the working surface and add closed end sealed rivets in. I do plan on sealing all rivets with epoxy after the boat is sanded, and before I prime/paint it.

I am using a handheld riveting tool for the 1/4" dia rivets as my rivet gun only goes to 3/16" (unfortunate mistake, but thankfully only have about 15 rivets that need the bigger rivets). Is that something I should be concerned about?

The problem I have is some of my newer rivets are slightly too long and I am afraid at some point will become snagged and mess the integrity of the seal itself. Is it advisable to trim the rivet at all with a small cutting wheel and hit the domed side with an air hammer to further secure the rivet? I know aircraft has a similar practice with trimming sealed rivets and bucking down/hammering the rivet end and was wondering if the same process could be applied here. It would also help my piece of mind knowing that they are sealed further by an air hammer.


Thanks for the help, been a lurker looking at the forums waiting to build a boat out, so I'm excited to have started the process!

 

[Tin Man]

Congrats on the boat purchase!
DaleH is member here and very well versed on all things rivets....perhaps he'll chime in.

 

[thill]

If you have access to both sides, go online or to Grainger or The Fastener Store and buy some 1/4" and 3/16" SOLID rivets.

You can get as fancy as you want, but the idea is to push the fastener through with the head on the outside, and have someone hold something heavy against it. (like a sledgehammer) Then expand it by hitting it with a hammer until it's tight.

You don't have to hit it crazy-hard, just try to hit it squarely. It will quickly expand and tighten up and feel "solid." Stop at that point and test, and tighten more, if needed. Just don't beat it until it's too thin. Look at the factory rivets - that's about what you want.

Once you use solid rivets, you won't use pop rivets nearly as much, especially below the waterline. I've gotten where I don't epoxy or seal a leaky boat, I just find the leaky rivets and replace them. A better repair, in my opinion, and I've had outstanding success.

Here are some rivets that may work in your application. For hand-peening, I generally like round head rivets, but Universal or Brazier heads work too.

https://www.zoro.com/zoro-select-so...aluminum-body-50-pk-30a0810-ea-50/i/G3293202/

 

[thill]

The problem I have is some of my newer rivets are slightly too long and I am afraid at some point will become snagged and mess the integrity of the seal itself. Is it advisable to trim the rivet at all with a small cutting wheel and hit the domed side with an air hammer to further secure the rivet? I know aircraft has a similar practice with trimming sealed rivets and bucking down/hammering the rivet end and was wondering if the same process could be applied here. It would also help my piece of mind knowing that they are sealed further by an air hammer.

If you are using 1/4" rivets, you want the shaft length to be the material thickness, plus 1/4"

Most Pop-type rivets CANNOT be cut and peened. You may end up cutting the expansion plug, and then be left with a thin, hollow tube with no strength. If they are done right, leave them be, otherwise I'd strongly recommend you switch to solid rivets.

You may be able to just peen them with an air hammer to lower the profile without cutting, but I can't recommend that.

An air hammer is fast, and if you have the right tip, it works great, but it's not necessarily any better than hand-peening. If I only had a dozen to do, I would hand-peen, as I would know exactly how tight I made them.

If doing a lot of rivets, using an air hammer and the proper anvil is the way to go. Will save a bunch of time, and you will get the feel for it, after a little practice.

 

[thill]

... And DaleH IS the man!

 

[Stimputello]

Bought an air hammer and found some old steel from work that I used to make an anvil/bucking bar. I'd rather fix it all at once than have to come back and repair it again in the future! Some holes are sized all the way to 5/16's believe it or not (ouch).

Have my work cut out for me as the boat was completely covered in flex seal on the bottom and found even more pinholes and even some corrosion/pitting that will need to put a plate over it as well. Removing the keel and cleaning all corrosion on the bottom has been a much bigger project than anticipated! Thank you all for the help!

 

[thill]

Removing the keel??? Yikes!