Replaced a dozen rivets, half leaking?

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







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

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.

BigTerp said:

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.

Click to expand...

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

finish bucking them with a hammer and a weight.

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 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

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 ?

acolic said:

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

Click to expand...

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.

Shaugh said:

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 ?

Click to expand...

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.


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lckstckn2smknbrls said:

acolic said:

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

Click to expand...

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.

Click to expand...

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




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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.

acolic said:

Shaugh said:

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 ?

Click to expand...

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.


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Click to expand...

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

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.

Shaugh said:

acolic said:

Shaugh said:

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 ?

Click to expand...

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

Click to expand...

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

Click to expand...

Sent from my iPhone using Tapatalk

ericman said:

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.

Click to expand...

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


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