nebbian said...

I broke my boom a couple of days ago, wasn't doing anything extreme just hooked in and it went snap. It was 5 months old.

The guy in the shop who is helping me with the warranty claim said that I should rinse the inside with fresh water, as well as making sure that the twist lock pins weren't engaged when the boom is left for a while. When you have a look at the inside of the aluminium tube, it is starting to pit and corrode. He said that the stainless in the clip pin would react with the aluminium tube (dissimilar metals).

Who rinses their boom after every session? Do you leave the clips in or out?

Never do (Except occassionally when has been stuck)

BTW have you got internet set up at home

I always rinse out my booms if a tap is available. If there is no tap I rinse it at home.

I have an older Neil Pryde aluminium boom. I had to wash and spray it with WD40 or it would seize up. Its around 10 years old and still okay.

Its been superseded by a Neil Pryde carbom boom and it doesn't seize up like the older boom but its such a nice boom that I rinse it too.

For the price of ally booms nowdays i just replace them every season or when they break no need to rinse

Also to rinse a boom properly you would have to dismantle it completely after every sail.... and i mean every nut screw and pop-rivet.... Waste of good drinking time if you ask this black duck

No other damage thank goodness. I was even able to plane home, holding both bits of the boom, now that's a weird feeling

Jaybee I've heard the same thing about aluminium and the oxidised layer, I think aluminium is a really reactive metal and they use aluminium powder in some explosives?

The strangest part of the whole thing was that it broke on the clamp side of the bung... so really I don't think that rinsing it would do any good because the fresh water wouldn't be able to get in there!

Meh I shouldn't complain, all's well that ends well

For what it's worth this is the advice from NP:

To give your booms and extensions a long life:
1. Take care to keep your booms & extensions out of the sun when not in use.
2. All sliding components must be free of sand & grit. Be sure to rinse out your boom in fresh water to prevent the build-up of dirt. This will also prolong the life of your aluminium booms which can be subject to corrosion over time.
3. Do not leave boom clips open when not in use.
4. Do not leave your extension inside your mast when not in use as it may corrode.

Paul Kelf said...

If your over 80kg or want longer life get a 32mm diameter Alloy Boom or a Carbon

Bugger, need to lose some kg's

Next one will be a 32mm I think! Thanks for the info Paul

Why dont you name the boom brand Stribo ? See if others have done the same thing to the same brand. I dont see a problem with naming brands on the Forum, whatever the brand is. Was it a Kommon brAnd ?

Ummm No Problems.... with that Kommon brAnd.... Nuthin Personal...and i don't like to Nit Pick... about things...[}:)]

trebuchet said...

For what it's worth this is the advice from NP:

To give your booms and extensions a long life:
... Blah blah blah....
3. Do not leave boom clips open when not in use.

Wot??? Are you sure that's right??
With the clips closed, the stainless steel pins are in contact with the aluminium
and set up an electrical cell resulting in corrosion. (dissimilar metals and all that stuff.)

The deal with aluminium corrosion is fairly unique and is this.
Pure aluminium is extremely reactive and easily corrodes in air and except for one small anomaly, all aluminium products would disintegrate into a white powder before they left the factory floor. The small anomaly this. The corrosion product, aluminium oxide, is a highly inert material and bonds very tightly to the aluminium which started corroding. Thus the corrosion process is self extinguishing. If the protective oxide layer is scratched, a new layer is imediately formed and protects the underlying aluminium.
The problem is that pure aluminium is quite soft so it is pretty much useless for high stress applications. The aluminium is therefore alloyed with other metals such as magnesium or titanium which make it very much stronger, but at the cost of diminishing the self preservation qualities of pure aluminium.
This can be sort of fixed by either fusing a thin layer of pure aluminium over the surface, (called Alclad) or more commonly just forcing the alloy to make a thick layer of protective oxide by anodising it. (That's all anodising is, just forced corrosion by electrical means)
Soooooo, booms are made of aluminium alloy for strength reasons and anodised for anti corrosion reasons. The trouble is, when you slide the boom in and out with a bit of salt or sand, the anodising layer is scratched and the self healing properties of the alloy, while there is some, is not sufficient to reinstate the protective oxide layer. And the final bad news is, aluminium alloys have very poor tear resistance. Thus once a fracture starts it can procede to total failure within a second.
So it can all come as a bit of a surprise when you end up in the drink holding a two piece boom.

pweedas said...

trebuchet said...

For what it's worth this is the advice from NP:

To give your booms and extensions a long life:
... Blah blah blah....
3. Do not leave boom clips open when not in use.

Wot??? Are you sure that's right??
With the clips closed, the stainless steel pins are in contact with the aluminium
and set up an electrical cell resulting in corrosion. (dissimilar metals and all that stuff.)

The deal with aluminium corrosion is fairly unique and is this.
Pure aluminium is extremely reactive and easily corrodes in air and except for one small anomaly, all aluminium products would disintegrate into a white powder before they left the factory floor. The small anomaly this. The corrosion product, aluminium oxide, is a highly inert material and bonds very tightly to the aluminium which started corroding. Thus the corrosion process is self extinguishing. If the protective oxide layer is scratched, a new layer is imediately formed and protects the underlying aluminium.
The problem is that pure aluminium is quite soft so it is pretty much useless for high stress applications. The aluminium is therefore alloyed with other metals such as magnesium or titanium which make it very much stronger, but at the cost of diminishing the self preservation qualities of pure aluminium.
This can be sort of fixed by either fusing a thin layer of pure aluminium over the surface, (called Alclad) or more commonly just forcing the alloy to make a thick layer of protective oxide by anodising it. (That's all anodising is, just forced corrosion by electrical means)
Soooooo, booms are made of aluminium alloy for strength reasons and anodised for anti corrosion reasons. The trouble is, when you slide the boom in and out with a bit of salt or sand, the anodising layer is scratched and the self healing properties of the alloy, while there is some, is not sufficient to reinstate the protective oxide layer. And the final bad news is, aluminium alloys have very poor tear resistance. Thus once a fracture starts it can procede to total failure within a second.
So it can all come as a bit of a surprise when you end up in the drink holding a two piece boom.

Jesus! and they make aeroplanes out of the stuff...

jsut spend a bit more money and get a quality boom.. pryde make good booms i reckon.. not x3s though they suck the balls of dogs.. but x6 and x9.

Nebs, it aint corrosion (too soon), it's fatigue mate.
Lose some K's, use smaller sails or get a carbon boom

I was breaking booms too often (no wave sailing), so went carbon, feels heaps stiffer and handles the gusts better. Cost more than I could afford, but has paid for it's self now.

Oh yeh, don't forget you can turn the boom over to get back in, if you have too.

If you crash often or are reasonably hard on your gear (throw it on ground etc) do not by carbon. Carbon is 4-5 times the price of alloy so factor that you can have a new alloy boom every year for 5 years to that 1 carbon. Carbon has the added problem that if it breaks it is often catastrophic failure where both ends explode and its impossible to sail back (which happened to me 3 weeks ago). I can't rely on carbon in that one decent catapult means an expensive trip to the shop for another boom.

That said carbon lasts many more stress cycles than alloy, it can also be stressed further without breaking. There is the obvious weight and stiffness advantage, however modern alloy booms are better shaped and are almost as stiff as carbon- i've had a few carbon booms and they are mostly let down by extension clips and heads which can make them alot worse than a well thought out alloy boom. Carbon booms are alot better at feeling at one with the rig though, alloys just feel different.

On boom care.
I never was booms unless they get too much sand/mud on them. Apart from crash breakages the main failures i've seen are from:

Construction- On bolt on arm booms often the tube in the head is cut too short and ends on a critical load section of the boom.

Materials- The above head tubes are often made from thin stainless so over time incompatible metal/metal reaction occurs. On lesser extent this happens around bolts but is mainly cosmetic. *I have never seen a boom fail at the rear clips*

Plugs- Old booms most often fail at the plugs for the head bolts (pretty much unavoidable) or sealing plugs inside the boom. The salt tends to sit around the plastic or may be forced behind the plug by hosing out the boom. Similar corrosion affects where seen very fast in bolted floor factory carpeted alloy boats where the carpet sat up against the metal.

If you buy alloy, just retire it every 18months that way you dont have to worry. If you rinse it with warm water and spray some oil of something in it you then have a spare in the event that one breaks on a weekend.

Personally now I use Prolimit Hybrid, best of both worlds .

reading this is making me think I really should be taking better care of my gear.

But it hasn't let go yet. I have a HPL wave boom that I never wash or look after at all and is still working well. It got a good wash at Currumbin last week...that'll do.

Now I have said that it will prolly break tomorrow, oh well good excuse for a new one. But at $250 or so for an alloy and $900+ for a carbon they would want to be a hell of a lot better to get the nod. Somehow I don't think I will be talking the wife into that one.

I havnt broken any masts or booms yet however have put holes in boards and sails.

I wash my gear after every sail though. Boards, booms, masts and sails. Even Uni joints, base plates fins and all screws (vent plugs, fin screws etc.) if i been in salt water. Hang the sails up in the rafters for a couple days, leave boards out for a couple days out of the bag for the footstraps to dry and usually drain the booms for 3 or 4 days. Have to get all the grit out of masts and booms especially because otherwise booms become hard to slide and masts are hard to pull apart at the end of a session.

Bit different i know but it's what dad and i have done with all the gear ever since i started. I don't sail quite as often as most of you at the moment though.

Bubs