Monel or stainless steel - the same?

[john_morris_uk]

I see Monel rivets advertised and I also see stainless steel rivets advertised. What is the difference please? I feel I ought to know and I don't.

The real reason is that I need lots and lots of rivets (maybe 80 rivets) to attach my new mast steps to the mast and buying them at five in a pack for £3.50 from a chandlers isn't acceptable.

 

[Mudisox]

Presumably your mast is aluminium, and the steps are s/s. In which case you are going to have a different set of metals in contact and you are worried about corrosion. I'd just use aluminium based rivets myself, obtainable in large quantities at much cheaper prices than the swindlery will charge you- all for puttin g them into little packets.

 

[earlybird]

Monel is a copper nickel alloy, ~30/70% resp. Very corrosion resistant and fairly strong.
I don't think that it work hardens so much as SS, so might be easier to set.
Apart from that, I don't know what any practical differences might be.

 

[VicS]

Stainless steel is stainless steel. Monel is a copper nickel alloy.

Monel is easier to set than stainless steel... but use the same barium chromate (Duralac) paste

Dunno what tool you are going to use to set them.

I had difficulty finding the lazy tongs type recently although I eventually found a branch of a local tool hire company that claimed to have one.

Actually bought a cheap one from Tool Station. Expected rubbish for what I paid but proved to be quite satisfactory although I only set Monel rivets not stainless and not the largest size it would take either.

 

[john_morris_uk]

Thanks for the replies. I have some Durulac paste so will be putting it under the mast steps as I rivet them to the mast.

I was either going to use lazy tongs or one of these rivet guns: http://cgi.ebay.co.uk/ws/eBayISAPI....&_trkparms=algo=LVI&its=I&otn=2#ht_1267wt_913

In the same vein, what is the correct length of rivet vs hole diameter and thickness of metals you are fastening together? The aluminium extrusion of my mast might be 3mm or 4 mm thick plus the s/s of the mast step - say another 1mm - what length rivet is correct if its 4.8mm diameter?

 

[wotayottie]

There many different grades of stainless before you even get to the exotic non ferrous alloys like Inconel and monel. What you need for load bearing applications on your mast is the monel rivets.

There arent many rivets mad in stainless steel and most of those that are are either ferritic stainless or very soft austenitics. Neither are much use for mast fixings.

 

[john_morris_uk]

Presumably your mast is aluminium, and the steps are s/s. In which case you are going to have a different set of metals in contact and you are worried about corrosion. I'd just use aluminium based rivets myself, obtainable in large quantities at much cheaper prices than the swindlery will charge you- all for puttin g them into little packets.

I am not sure I want to trust my 80 something Kg on steps riveted on with aluminium rivets? I know that I will be still wearing a bosuns chair or harness as a safety backup to ascend, but I want to be confident that when I am mid ocean and have to go up the mast, the steps are secure. It appears that monel really is the answer.

The remaining problem is sourcing 80+ of the things at the correct length.

 

[SAMYL]

I see Monel rivets advertised and I also see stainless steel rivets advertised. What is the difference please? I feel I ought to know and I don't.

The real reason is that I need lots and lots of rivets (maybe 80 rivets) to attach my new mast steps to the mast and buying them at five in a pack for £3.50 from a chandlers isn't acceptable.

You can get monal rivets on ebay at a reasonable cost.

 

[Bobobolinsky]

Should be able to buy them by the box of 100 from good fastener suppliers. You need thickness of materials to be joined plus 2 diameters, any less and they don't pull up properly. Monel is a swine for work hardening, so you must pull up ideally in one stroke, so either lazy tongs or an air rivetter are a must.

 

[nickd]

Hi
Try these guys
www.inox.ie/acatalog/Rivets.html

They seem to have a comprehensive range at rerasonable costsand their service was excellent when i bought from them

I particularly liked the assorted A4 kit which I keep on the boat for emergencies

cheers

 

[john_morris_uk]

Hi
Try these guys
www.inox.ie/acatalog/Rivets.html

They seem to have a comprehensive range at rerasonable costsand their service was excellent when i bought from them

I particularly liked the assorted A4 kit which I keep on the boat for emergencies

cheers

Perfect - but what's a 'rivet plug' as mentioned at the bottom of the page?

 

[alexrunic]

or try theses

http://www.seascrew.com/browse.cfm?POP-RIVETS-MONEL---MAST-RIVERS-&l=0000000561

or these

http://www.sky-craft.co.uk/acatalog/Skycraft_Sales_British_Monel_270.html

 

[nickd]

Perfect - but what's a 'rivet plug' as mentioned at the bottom of the page?

No expert but i think its an insert into the hole on the rivet once you have clamped it up and the shank has snapped off

 

[NormanS]

Hi
Try these guys
www.inox.ie/acatalog/Rivets.html

They seem to have a comprehensive range at rerasonable costsand their service was excellent when i bought from them

I particularly liked the assorted A4 kit which I keep on the boat for emergencies

cheers

I also dealt with these people, and found them to be very good and very helpful. I used 6.4mm monel rivets for fitting my mast steps. The guy at Inox will give you advice about appropriate length etc. Their price is good, but be advised thet they are based in Eire, and their VAT rate is a lot higher than ours, (at present).

P.S. The plugs mentioned are little plastic things that plug the hollow rivets once the nail drops out.

 

[Leighb]

P.S. The plugs mentioned are little plastic things that plug the hollow rivets once the nail drops out.

Feeling paranoid, all these steel pins laying at the foot of the mast in, damp, contact with unprotected aluminium presumably cause corrosion form the inside out?

 

[VicS]

one of these rivet guns

I would rather have had one of those long handled type!

the trouble with the lazy tongs type is that not only do you fall "base over apex" when it pops but unless you hold the business end the little bit of the mandrel sticking out goes skidding across the work, taking the anodising off as it goes.

Regarding the length. Watch that. Some are labelled up with the "grip range" others with the actual length of the rivet under the head but excluding the ball end of the mandrel ( both types here in front of me!)

The 5mm (3/16") diameter ones labelled as 3mm grip range are approx 8mm long.
The 4mm diameter ones are 1 mm shorter)

On that basis to grip 4mm + 1mm you will need them 10mm long if not labelled with a "grip range".

You can always pull down slightly overlength ones but you wont make a strong joint if they are too short!

Also watch the diameters. the metric and imperial equivalents are not exact... Very annoying to drill a load of holes and then find them a tiny fraction too small ... esp when in stainless steel

 

[NormanS]

Feeling paranoid, all these steel pins laying at the foot of the mast in, damp, contact with unprotected aluminium presumably cause corrosion form the inside out?

Yes, I worried about that too. The mast steps were fitted when the mast was down, and once it was stepped again, the little bits of rivet nail all(?) fell to the bottom, where they could be pulled out of a convenient cable hole with one of these little magnets on a telescopic stick.

 

[Tradewinds]

Electric rivet guns

I was lent an electric rivet gun by a rigger a few years ago.

It worked a treat - it looked basically like a cordless drill. Quite expensive to buy though - several hundred pounds i believe.

Has anybody ever used this gadget which converts a standard drill or cordless into an electric riviter?

RiveDrill

More info here.

If it works it could be useful - especially in those places where you can't get the reach or grunt to operate a scissor or 2-handed lever rivetter.

 

[Danny Jo]

Whichever rivet you use, and I'm for Monel myself, remember that the steel pin that breaks off leaves a steel ball behind. I'm told by my rigger friends that these are a major source of electrolytic corrosion, and should be knocked out.

So before plugging the rivet with the plastic insert, which is designed simply to reduce water ingress, use one of the broken off pins as a punch to drive, using a hammer, the plug out the back of the rivet. There wouldn't be much point in using plastic plugs if you don't knock out the remains of the steel pin/ball.

 

[charles_reed]

Monel copper/nickel, as strong (in my experience) as stainless steel and far easier to work.

As to using Duralac paste - the monel rivets I put into my mast, when Duralac wasn't as readily available as now, 19 years ago showed no sign of corrosion when I drilled them out last year.

I use a long-handled riveter - made in Yorkshire - and far more powerful and exact than the lazytong types - the only trouble is stowing its length. Pulls up to 10mm aluminum and 8mm stainless.
Sorry I can't give you the name and address, boat and I are 1380nm apart.