Monel pop rivets - very good but what to do with the steel pin inside?

[Poignard]

I have to pop-rivet some eyelets to an aluminium boom. I plan to use monel rivets but part of the mild steel pin will remain inside the rivet when I've clinched it.

What to do with this pin? Knock it through and it will lurk inside the boom and rust. Leave it where it is and it will also rust. Either way seems likely I'll end up with rust stains weeping out.

Advice appreciated.

 

[CAPTAIN FANTASTIC]

Monel steel does not rust and you do not push the pin inside. The rivet will expand inside and the pin will break at a point almost in line with the visible part of the rivet, the remaining of the pin which broke off will be disposed.

 

[Poignard]

So the pin is also monel? In that case, I'll do as you suggest.

I had assumed it was steel because I can pick up the pre-pack (from Holts Marine Ltd) with a fridge magnet.

 

[skipmac]

So the pin is also monel? In that case, I'll do as you suggest.

I had assumed it was steel because I can pick up the pre-pack (from Holts Marine Ltd) with a fridge magnet.

I would assume the entire rivet is Monel. Think it would cost more in higher production costs to use two materials to make a rivet than it would save using a bit more Monel.

Also, Monel is slightly magnetic. Same with many SS alloys.

 

[CAPTAIN FANTASTIC]

So the pin is also monel? In that case, I'll do as you suggest.

I had assumed it was steel because I can pick up the pre-pack (from Holts Marine Ltd) with a fridge magnet.

Monel is magnetic as it contains small % of iron, but is excellent for saltwater, resisting corrosion.

 

[Poignard]

Thank you. I am reassured.

 

[VicS]

So the pin is also monel? In that case, I'll do as you suggest.

I had assumed it was steel because I can pick up the pre-pack (from Holts Marine Ltd) with a fridge magnet.

I am 99% sure that monel rivets have steel mandrels . Easy to check to see if the mandrel is attracted to a magnet


The Monel is only slightly magnetic at room temperatures

 

[Poignard]

I am 99% sure that monel rivets have steel mandrels . Easy to check to see if the mandrel is attracted to a magnet

Well that's what I did (see above posts) but the Captain says monel is also magnetic

 

[DickB]

I have used monel rivets twice, once for the radar bracket on the mast and the other as replacements for hatch hinges. Both times they were capped so that water could not get through the centre pin, and the centre stayed in after breaking when "popped". No rust in either counts so I am guessing the pins are monel too. Bloomin hard work to "pop". The monel is hard!!!

cheers,

 

[VicS]

Well that's what I did (see above posts) but the Captain says monel is also magnetic

The Monel is only slightly magnetic at room temperatures

I dont know about being due to the fact that it contains iron (2.5% max) More likely because it's 63% nickel

 

[Boo2]

So the pin is also monel?

I doubt that very much.

Boo2

 

[Plevier]

Certainly in the case of my Selden carbon bowsprit the pins are steel - big ugly rust smears. I have now knocked them out.

 

[prv]

Steel pins in mine too. What's this nonsense about it costing more to use two materials? The pin and the rivet are two separate parts, why would the material of one affect the manufacture of the other?

Mine were in the mast, so the bits fell to the bottom and after a trip or two they shook themselves out onto the deck and were disposed of. The rivets came with plastic plugs that were supposed to be inserted to seal them, but they didn't look very convincing.

Pete

 

[PlankWalker]

As Vics said Monel rivets have steel mandrels.
After setting rivet, punch out head of mandrel using another mandrel held with pliers, dab silicone in hole and wipe off.
Drill hole in base of mast and fish for punchings with powerful magnet, do this while Duralac is still liquid!

Plank

 

[MM5AHO]

Good quality monel rivets come with a plastic plug to insert into the hole that's left after popping the rivet.
The pin is steel, not monel.

 

[Norman_E]

I recently used some 4.8mm monel rivets and they took quite a bit of force with a lazy tong riveter to set them. I doubt I could do it with the one handed squeeze type rivet gun.

 

[Croftie]

Pins steel or stainless steel.
http://www.hansonrivet.com/blind-rivets-monel-steel.htm
http://www.hansonrivet.com/blind-rivets-monel-stainless.htm

 

[VicS]

I recently used some 4.8mm monel rivets and they took quite a bit of force with a lazy tong riveter to set them. I doubt I could do it with the one handed squeeze type rivet gun.

I am sure you would not. I bought a cheap lazy tong type a couple of years ago when I wanted to set some ... cheaper and easier than hiring. Toolstation !

I d prefer the long two handled type though! but what i bought did the job, its on the shelf if I need it again, but thats very unlikely ... just something else to be chucked out when I'm gone

 

[CAPTAIN FANTASTIC]

If the mandrel is pushed in, then the shear strength of the rivet will be reduced enormously.

 

[VicS]

If the mandrel is pushed in, then the shear strength of the rivet will be reduced enormously.

But surely they break leaving very little more than the ball on the end behind. Not enough to contribute to the shear strength.