Replaced a dozen rivets, half leaking?

[acolic]

Hi

I could use some expertise.

Last Thursday I replaced a dozen rivets. I have attached a picture of the rivets used which are aluminum 1/2" length 3/8 diameter closed pop rivets.

Before I inserted them in the hole I coated the inside of the rivet with 3M 5200 adhesive. I used an air riveter to set them.

I then went fishing Saturday through today (Monday). When I got home I refilled the boat with water to verify if any of the rivets were still leaking and 6 of the 12 are.

I use the same technique for all the rivets so where did I go wrong?

Are the rivets I used correct?

Should I have used 3M 4200 instead of 3M 5200?

For the leaking rivets what do I do at this point? Do I drilled him out sand the adhesive off ( can I) and reinstall them or just put more adhesive along the edge of the rivets?

I appreciate any help.

Thanks

Alex

Sent from my iPhone using Tapatalk

 

[lckstckn2smknbrls]

What is the total thickness of the aluminum you riveted together?

 

[BigTerp]

In my experience blind rivets are inferior to solid rivets below the water line. They do not seal out water as well as a solid rivet will. I know some have done it with success, and others have even used stainless nuts and bolts with some 5200 below the water line. But with the flexing/stress on an aluminum hull blind rivets can fail and allow water in. I have a ton of blind rivets above the water line and from time to time I'll find one that has worked loose or even where the head has popped off. Not a big deal above the water line, but below the water line you can see how this would be a problem. IMO, a properly set solid rivet with a bit of 5200 is second only to welding.

 

[CMOS]

In my experience blind rivets are inferior to solid rivets below the water line. They do not seal out water as well as a solid rivet will. I know some have done it with success, and others have even used stainless nuts and bolts with some 5200 below the water line. But with the flexing/stress on an aluminum hull blind rivets can fail and allow water in. I have a ton of blind rivets above the water line and from time to time I'll find one that has worked loose or even where the head has popped off. Not a big deal above the water line, but below the water line you can see how this would be a problem. IMO, a properly set solid rivet with a bit of 5200 is second only to welding.

I second the 3M 5200. Also, I've never had a problem with blind rivets below the water line (when using the 5200...). YMMV.


CMOS

 

[ericman]

finish bucking them with a hammer and a weight.

 

[acolic]

Thanks,

I could use solid rivets but it would mean pulling out a casting deck and floor and I am trying to ovoid that.

The metal being joined is slightly thicker then 1/8".

I used an online calculator which suggested that a 1/2" rivet was the correct length.

Thanks

 

[earl60446]

I think 3m5200 has 2 setup times, depending on which one you use. There are 2 types, one takes a day, the other takes a week.
Possibly the inside support metal separated from the hull causing a poor mechanical seal.
When I look at the picture, if that is a 3/8" diameter rivet, then the rivet must be way longer than 1/2".
Tim

 

[Shaugh]

I suspect your problem is the air riveter. Blind rivets require a bit of technique to get a good draw. The best way is to slowly tighten the rivet... giving it time to draw the pieces together. Then to re-grip the tool and pop it.

If you don't do it that way the rivet can break before it's had a chance to draw the 2 surfaces together... I imagine that air riveter works quite fast doesn't it ?

 

[lckstckn2smknbrls]

Thanks,

I could use solid rivets but it would mean pulling out a casting deck and floor and I am trying to ovoid that.

The metal being joined is slightly thicker then 1/8".

I used an online calculator which suggested that a 1/2" rivet was the correct length.

Thanks

I would say the 1/2" rivet is to long. You want a rivet with a grip length of about 1/4" for 2 pieces of 1/8" material.

 

[acolic]

I suspect your problem is the air riveter. Blind rivets require a bit of technique to get a good draw. The best way is to slowly tighten the rivet... giving it time to draw the pieces together. Then to re-grip the tool and pop it.

If you don't do it that way the rivet can break before it's had a chance to draw the 2 surfaces together... I imagine that air riveter works quite fast doesn't it ?

Yes compared to my hand held riveter worked a lot slower. I wish I marked which rivets were hand installed and which were sir installed.


Sent from my iPhone using Tapatalk

 

[acolic]

Thanks,

I could use solid rivets but it would mean pulling out a casting deck and floor and I am trying to ovoid that.

The metal being joined is slightly thicker then 1/8".

I used an online calculator which suggested that a 1/2" rivet was the correct length.

Thanks

I would say the 1/2" rivet is to long. You want a rivet with a grip length of about 1/4" for 2 pieces of 1/8" material.

So should I drill out the leaking rivets and reinstall 1/4 length rivets?




Sent from my iPhone using Tapatalk

 

[ericman]

I would say the 1/2" rivet is to long. You want a rivet with a grip length of about 1/4" for 2 pieces of 1/8" material.



So should I drill out the leaking rivets and reinstall 1/4 length rivets?

No, 1/4" grip length does not mean 1/4" long rivet. It just means that the rivet is capable of joining sheets totaling 1/4" thickness, so the shaft length is actually a bit over 1/2". You have the right ones.

And they are not 3/8" diameter rivets. I've never seen 3/8" blind rivets. I've never seen 3/8" rivets in boats period. The most common diameter rivet in a boat is 3/16". The only reason to go bigger is if you are riveting your transom together OR if an existing rivet hole is worn out (too big) then you just drill to 1/4" and replace with a 1/4" rivet.

Like I said in an earlier post, just finish bucking the rivets. That will squeeze everything up tight. If need be, smear some jb-weld over the rivet-head to seal.

 

[Shaugh]

I suspect your problem is the air riveter. Blind rivets require a bit of technique to get a good draw. The best way is to slowly tighten the rivet... giving it time to draw the pieces together. Then to re-grip the tool and pop it.

If you don't do it that way the rivet can break before it's had a chance to draw the 2 surfaces together... I imagine that air riveter works quite fast doesn't it ?

Yes compared to my hand held riveter worked a lot slower. I wish I marked which rivets were hand installed and which were sir installed.


Sent from my iPhone using Tapatalk

It doesn't happen often, but there are times when "too quick" is a bad thing.... this is one of them...

 

[acolic]

I found a formula to calculate the correct length of a rivet:

Thickness of materials + 1.5 (diameter of the rivet)

If this is correct then for joining 1/4" material I should have used a rivet length of:


=1/4 + 1.5 (3/16)
=1/4 + 9/32
= 17/32

A little longer then 1/2" so I guess it was OK my using a 1/2" rivet.

I suspect your problem is the air riveter. Blind rivets require a bit of technique to get a good draw. The best way is to slowly tighten the rivet... giving it time to draw the pieces together. Then to re-grip the tool and pop it.

If you don't do it that way the rivet can break before it's had a chance to draw the 2 surfaces together... I imagine that air riveter works quite fast doesn't it ?

Yes compared to my hand held riveter worked a lot slower. I wish I marked which rivets were hand installed and which were sir installed.


Sent from my iPhone using Tapatalk

It doesn't happen often, but there are times when "too quick" is a bad thing.... this is one of them...

Sent from my iPhone using Tapatalk

 

[acolic]

I would say the 1/2" rivet is to long. You want a rivet with a grip length of about 1/4" for 2 pieces of 1/8" material.



So should I drill out the leaking rivets and reinstall 1/4 length rivets?

No, 1/4" grip length does not mean 1/4" long rivet. It just means that the rivet is capable of joining sheets totaling 1/4" thickness, so the shaft length is actually a bit over 1/2". You have the right ones.

And they are not 3/8" diameter rivets. I've never seen 3/8" blind rivets. I've never seen 3/8" rivets in boats period. The most common diameter rivet in a boat is 3/16". The only reason to go bigger is if you are riveting your transom together OR if an existing rivet hole is worn out (too big) then you just drill to 1/4" and replace with a 1/4" rivet.

Like I said in an earlier post, just finish bucking the rivets. That will squeeze everything up tight. If need be, smear some jb-weld over the rivet-head to seal.

You're correct I meant to say 3/16" rivet diameter not 3/8".


Sent from my iPhone using Tapatalk