Pop rivets or self tapping scews for mast Conduit

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retsina

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I will be installing a Radar on an aluminium mast, near the spreaders. Do I use self tapping screws or pop rivets for the radar bracket and for the pastic cable conduit?

Pop rivets usualy have aluminium head and mild steel rod or stainless steel rod. Is there a danger that the the mild steel part will rust? is the stainless steel compatable with the Aluninium mast?

Is it better to use self tapping screws? what type?

Many Thanks
 
Not self tappers I would think.

Monel or stainless steel pop rivets not the aluminium ones. (stainless ones will need a good tool to set them)

Use a chromate paste such as Duralac (barium chromate)
 
To fix the bracket to the mast use monal metal pop rivets and coat them with duralec to isolate them from the alloy mast.

You will need to buy, beg or borrow a lazy tongs type riveter as the 6mm rivets normally used require quite a bit of presure to set.

For an external duct on the mast for the wiring you could probably use self tappers but again dip them in Duralac.

Iain
 
[ QUOTE ]
You beat me to it Vic.

[/ QUOTE ] Makes a change I usually find three or four people have beaten me!

Was going to add perhaps aluminium rivets will be OK for the conduit. I think it is possible to get them with a mandrel that is not mild steel.

With the lazy tongs you need a good firm support and you have to be careful not to scratch the mast surface as the tool skids off with a little bit of mandrel sticking out! Maybe the long handled, two handed type would be better.

www.Seascrew.com or www.a2a4.co.uk for the rivets. Many chandlers stock the Duralac paste
 
I supose it depends upon what the ducting is made from. Some plastics would certainly just pull through with monel rivets but might be ok with aluminium as you have sugested.

I'm afraid that I have experience of what you were saying about the way lazy tongs bounce about when riviting a mast.

In my garden is a 48 ft mast which I made from scratch using a sparcraft section. (Twin spreader, keel stepped with mast dam, radar scanner, deck light, tricolour/white, wind sensor, VHF aerial, twin foresail, spinny and main halyards, removable babystay, removable cutter/storm jib stay as well as a winch, spinny pole track,etc. It was quite a big task especially cutting out all the holes.

Virtually all the rivets were 6mm monel (with white inserts in the centres) but for joining stainless to stainless I used 5mm stainless ones.

There was not a problem with the wiring ducting as the mast has three small internal T tracks designed to take split ducting.
Also all the wiring exits the mast below decks.

I have plenty of spare 5mm stainless rivets (only about 12mm long) if anyone wants any.

Iain
 
quote:
In my garden is a 48 ft mast .........................
.....................................................................
You trying to move house then?

Sorry.. it was just the picture it created...

Re the rivits I would think about self-tappers for the ducting in case you need to remove it at some point.
 
You could consider drilling and tapping for SS screws. Would give you a more workmanlike job. It has the merit of giving the option of not intruding into the mast space with the ends of self tappers if it is a consideration.
 
The problem with monel rivets is they are so dam hard they are nigh on impossible to remove. I installed radar brackets, wasn't entirely happy with the outcome, but have been unable to drill the heads off the rivets, the rivet just spins. Make absolutely certain about the positioning of the brackets - you have one chance.
By the way anyone any ideas on how to remove said rivets?
 
[ QUOTE ]
The problem with monel rivets is they are so dam hard they are nigh on impossible to remove. I installed radar brackets, wasn't entirely happy with the outcome, but have been unable to drill the heads off the rivets, the rivet just spins. Make absolutely certain about the positioning of the brackets - you have one chance.
By the way anyone any ideas on how to remove said rivets?

[/ QUOTE ]

Angle Grinder


also

to poster above, if using the two handled riveter that looks a little like a large bolt cutter, be careful, I near broke my jaw when the first rivet went and the things close at around 500mph. I lost an hours working time as I hopped around the yard with tears sloshing about and I am no whimp.. They were 6.4mm rivets on my x-trees, much heavier than the ones on my radar strut, but all the same, they give you a fright the first time you snap the popper.
 
I have used 4.8mm Monel rivets for installing a big Air X wind generator mounting on my mizzen and the same size for fitting 'Bean Stalk' mast steps.

I used a ladder for installing the generator mounting and for the mast steps as far as the spreaders climbed up the mast on the steps as I instaled them to fit the next ones up..... I say this just to qualify the use of a 'Lazy Tong' riviter which I found I could use okay with one hand whilst hanging on with the other.

Not recomended by the H and S chaps but worked okay for me.

BTW the 4.8 mm monel rivets are 1 quid each if you buy 'em at a swindlery so if Ian S is unloading some its worth giving a call.

You have to be careful to use the correct drill and have a few spare bits as they dig in and snap.

I bought my riviter from one of those Draper Tool Stop shops it was about a tenner and a bloody useful tool to have.

Don't forget the Duralak yellow stuff.

Regards Nick
 
I also put my Radar and Wind Gen up the the mizzen using a ladder but opted out of using pop rivets due to the difficulty factor and problems getting hold of a riveter with a small diameter head, so I used large self tappers with a barrier and covered them in silicone sealant.
They have been up now for six years and all ok.
 
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