1978 16 kingfisher

[Star64!]

Pulled floor out of leaky Starcraft and found a couple of leaks when couple of inches of water were in bottom of boat. Was told to float boat to get better idea of issues. When in water I could see huge problem. All rivets down center of boat were letting in water. Back side of rivet dissolved or corroded and all that was left manufactured head on bottom of boat and shaft in hole. Slight tap with punch from inside and rivet dropped out. They are 3/16 rivets. Hole is in perfect shape no signs of corrosion.
Is this normal for 44 year old Starcraft? Rivets thru keel, floor and rib are still ok. Only 2 rivets between every rib has failed. Could they have installed them poorly at factory or used wrong rivet?

 

[Watermann]

For some boats it's been an issue, I had to replace 100's of solid rivets on my 79 SS because the heads would fall right off when tapped.

 

[SHSU]

Admiral and I redid all on our 1983/84 SS16. Ours though were related to corrosion.

SHSU

 

[Moserkr]

For mine, they were mainly caused by an impact with a log by a previous owner, and poor bunks on the trailer. If the lost rivets are aligned, I would wager it has to do with an external force. All of my bad rivets followed a pattern due to those 2 factors. Could also be cause by running it too hard in rough seas. Just some thoughts.

 

[Star64!]

My bad rivets must be due to corrosion. I haven’t found separated pieces. Confusing part is only rivets between ribs are bad. 4 rivets in each rib look good. Rivets between ribs are missing backs from bow to stern. Could they have used different rivet. Material is 1/8” between ribs and 3/16” with rib.

my rivets have domed 3/8 head and 3/16 shaft. I would like to replace them by myself but am wondering how easy it is to damage aluminum sheets. Sounds like all with similar issues had success. Let me know experience and tools used. Length of rivet also

 

[Star64!]

This is the project. Title says it is 1978

 

[SHSU]

I would like to replace them by myself but am wondering how easy it is to damage aluminum sheets. Sounds like all with similar issues had success. Let me know experience and tools used. Length of rivet also

Its not hard to do, just need an extra hand to handle the bucking bar. That being said, tools usually consist of:

Rivet Gun (Not impact hammer)
Brazier Head/Modify Brazier head bit
Bucking bar
5200

As for size, reference @Watermann 's great sticky
https://forums.iboats.com/threads/rivets-rivets-and-more-rivets-repaired.741809/

In the end, watch a couple youtube videos on airplane riveting and practice on a scrap piece and you should be good to go.

SHSU

 

[Watermann]

Riveting these old boats may seem daunting but it's actually fun once you get into it, I think part of it is knowing that you're making the boat stronger than when it was new.

 

[Star64!]

Started replacing rivets using 1/4 1100 aluminum rivets. Next step is to remove brace from stern to access bad rivets on stern behind brace. I do not have Cleco rivet clamps so will try to bolt in using half of rivet holes. Install remaining rivets then remove bolts and finish rivets. nervous about water testing. Hope not making a leaky boat worse

 

[SHSU]

Started replacing rivets using 1/4 1100 aluminum rivets. Next step is to remove brace from stern to access bad rivets on stern behind brace. I do not have Cleco rivet clamps so will try to bolt in using half of rivet holes. Install remaining rivets then remove bolts and finish rivets. nervous about water testing. Hope not making a leaky boat worse

While Cleco's are nice, many of us have used bolts through or blind rivets to hold pieces in place while bucking the solids.

As for making it worse, can't be. They had failed so even if you have a miniscule leak, its still way better then an open hole. You are doing the right thing.

QQ:
Any particular reason why you are jumping to 1/4 instead of just using 3/16 rivets?

SHSU

 

[Moserkr]

I bought 1100 AL rivets at first, then went to T4. Arent T4 stronger for use on the hull? Remember reading thats what was recommended and what starcraft originally used.

 

[SHSU]

Yep, 2117T4 is the way to go.

SHSU

 

[Star64!]

I did use 5/32 diameter by 3/8 length. Most of my failed rivets in between ribs on keel. Still have to replace bunch of rivets in transom at floor near center. Then will reinstall brace from transom to floor. I have 1/4 “ of rivet to work in transom holes. My 1/2” rivets left 3/8” which I found much more difficult to make nice shop end. I know there was strong recommendation to use T4 rivets. How much harder are they to work?

 

[Watermann]

I did use 5/32 diameter by 3/8 length. Most of my failed rivets in between ribs on keel. Still have to replace bunch of rivets in transom at floor near center. Then will reinstall brace from transom to floor. I have 1/4 “ of rivet to work in transom holes. My 1/2” rivets left 3/8” which I found much more difficult to make nice shop end. I know there was strong recommendation to use T4 rivets. How much harder are they to work?

Pure soft 1100 Al rivets are fine if it's not structural but the harder "T4" rivets are more closely matching the alloy hardness of the hulls 5052 Al making for a more lasting connection as well as resistant to head damage. They are more difficult to set than the pure Al 1100 requiring a couple more seconds of air hammering.