Facing the task of conditioning or refurbishing an aluminium alloy mast and boom, I am interested to know what others have done and any useful relevant advice. My spars show some surface corrosion, but not pitting. The appearance is similar to aluminium that has shed a painted surface of some sort. Am aware that some alum. spars are painted, possibly powder coated and others anodised, no doubt some are not surface treated at all. Beyond a simple soap suds wash-down to restore to a pristine surface (if necessary at all?), I am contemplating a light buff using a fine grit wet-dry paper. This may be inadvisable particularly if the surface was anodised originally, for obvious reasons. I have also heard that a wax of some form may be applied, after a good brush wash, to protect against weathering. Powder coating sounds ideal but maybe impractical or too expensive. Do you have any pearls of wisdom to share for a cleanup/protect/spruce-up of alum. spars? Thank you, Nautique.
From my personal experience, I think the anodising way is by far the best option.
Without knowing the mast height of your yacht, I expect you would be struggling to find a powdercoater that can do much beyond 6m and very few up to 10m.
If there is someone then, a three step powdercoating process including etch, epoxy primer and a special powder is available.
We employed this system on many aluminium Lifeguard towers built and it seems to hold up well.
As with anything these days where any labour is required,your effort in preparation such as sanding,will save you a pile of money.
Contact an anodising plant in one of the main centres and insist on a 25um(micron) finish or better quote.
Transporting is the other point, being more than likely, a long load.
Good luck-CR.
Thanks for the sound advice CR. At 10M I suspect powder coat is a length 'too far'. Will research anodising before I take an abrasive to the spars. Thank you again. Nautique.
Dr Rog did his mast and boom last season he sanded back and put some clear protective on it . Dont think you can buy that any more . " Dr Rogs masts were not anodized"
My mate on a Walker H28 just used house white enamel. and when its scratched and when he feelings like it he just touches it up.
My masts are on my list this winter ( ketch ) and there old anodized masts and booms. You cant re anodized them wont work and when you sand the mast that are anodized but you cant remove all the anodizing as it soaks into the aluminium when there anodized.
For me I have another look before I start and reaccessed what condition they are in .
Last time I looked I was going to sand them back and clean and try and make a good painting surface on the anodizing and paint with two pack using a good under coat first. My masts have also corosion spots here and there as well as halyard and sail flap which has taken the anodizing off .
Thanks HGO2. Hopefully a professional anodiser can advise the feasibility and preparation necessary for successful re-application. If not feasible, the other option would be quality marine paint - but I am yet to learn more about the credibility of waxing aluminium and suitability, durability for marine application. Cheers, Nautique.
Select to expand quoteNautique said..
Thanks HGO2. Hopefully a professional anodiser can advise the feasibility and preparation necessary for successful re-application. If not feasible, the other option would be quality marine paint - but I am yet to learn more about the credibility of waxing aluminium and suitability, durability for marine application. Cheers, Nautique.
I talked to my rigger about that and he does not think you can re anodize and he had a anodizer next door who He asked for me .
If there originally anodized the best you can do is clean them up and leave them . or paint them . if you choose two pack you need to make up a small mix now and then to touch up the scuffs ands scratched or choose a enamel paint and just touch them up.
You cant sand the anodizing off completely as it would removed to much metal from the masts and weaken them.
There was a air craft anodize removing liquid on the market a few years a go its been banned now as it is carcinogenic no longer available
www.cruisersforum.com/forums/archive/index.php/t-137972.html
www.google.com.au/search?q=clear+Tectyl&oq=clear+Tectyl&aqs=chrome..69i57&sourceid=chrome&es_sm=93&ie=UTF-8
www.valvolineeurope.com/english/products/tectyl/aftermarket/cid(9132)/tectyl_multipurpose_clear
www.nyalic.com/marine/
Some in the first link on cruiser forums suggested some of the above 
good luck with what ever you do
www.nyalic.com/marine/ < this one looks interesting
Your latest post makes sense HGO2 - I have read elsewhere that re-application of alumina (via electrolysis) is not feasible, and to remove existing inevitably involves removing some level of metal, that sounds self-defeating. Thanks for making the enquiry, I'm leaning towards paint, wax or scrub and leave, a question of what cosmetics I want to live with - it's an interesting problem to ponder though. I have seen the result of buffing and waxing aluminium found on automobiles, but the marine environment may be a greater challenge for coatings. I'm not sure what the "two pack" you and others have referred to is/involves - some type of paint I assume? Thanks, Nautique.
You are right HGO2, that Nyalic Marine Coating product does look very interesting. Tks, will research. Nautique.
There is a product made here in town called "Metal Gleam" made by Nowra Chemicals. I used to buy it in 20 litre containers. Its just a mixture of acids. I used to use it to clean fibre glass and to prepare paint for overcoating. It's widely used in the fishing industry here. Applied to aluminium boats or bare alloy masts it brings them up as new. For clear coating I would just use automotive clear coat sprayed straight over the alloy as soon as possible after etching with metal gleam.
Select to expand quoteRamona said...
There is a product made here in town called "Metal Gleam" made by Nowra Chemicals. I used to buy it in 20 litre containers. Its just a mixture of acids. I used to use it to clean fibre glass and to prepare paint for overcoating. It's widely used in the fishing industry here. Applied to aluminium boats or bare alloy masts it brings them up as new. For clear coating I would just use automotive clear coat sprayed straight over the alloy as soon as possible after etching with metal gleam.
Could you use metal gleam on anodised masts ?
Select to expand quoteHG02 said..Ramona said...
There is a product made here in town called "Metal Gleam" made by Nowra Chemicals. I used to buy it in 20 litre containers. Its just a mixture of acids. I used to use it to clean fibre glass and to prepare paint for overcoating. It's widely used in the fishing industry here. Applied to aluminium boats or bare alloy masts it brings them up as new. For clear coating I would just use automotive clear coat sprayed straight over the alloy as soon as possible after etching with metal gleam.
Could you use metal gleam on anodised masts ?
Have not tried it but imagine it would be fine.
if you get to the point of wanting to paint it, I had good results actually with Killrust on a previous boat.
After a sand, wash, and using the Killrust etch primer, the white top coat was easy to apply and gave a good gloss finish, and being a single pack epoxy, it was reasonably tough as far as a paint goes.
For our mast which had the original white paint finish we just wire brushed the corrosion and used International Interprotect.
For the boom we just used an aluminium fence paint from Bunnings.
Select to expand quotecrustysailor said..
if you get to the point of wanting to paint it, I had good results actually with Killrust on a previous boat.
After a sand, wash, and using the Killrust etch primer, the white top coat was easy to apply and gave a good gloss finish, and being a single pack epoxy, it was reasonably tough as far as a paint goes.
Hey Crusty were the masts anodized on the boat you painted?
When does aluminum start to corrode?
As soon as you paint it or try to remove oxygen from it.
When does paint get scratch marks?
As soon as you paint it.
By trying to cover the alloy it can't protect itself but will provide excellent points at any breach from a scratch for aluminum oxide to destroy the spar. Its the same reason I won't paint my alloy tender.
I must be aesthetically challenged because I don't really "get" the need to cover up a nice shiny alloy spar. I stripped mine using one of those paint temover plastic blue grinder discs and the finish is like a brushed aluminum. Its 3yrs on and it still looks like it was done yesterday. I was initially worried that the boom would be too hot to the touch after midday but it's been fine. The only possible points of corrosion are under the duralac . which I'll redo when it looks bad.
Rust never sleeps and neither does aluminum oxide.
Select to expand quoteHG02 said..crustysailor said..
if you get to the point of wanting to paint it, I had good results actually with Killrust on a previous boat.
After a sand, wash, and using the Killrust etch primer, the white top coat was easy to apply and gave a good gloss finish, and being a single pack epoxy, it was reasonably tough as far as a paint goes.
Hey Crusty were the masts anodized on the boat you painted?
HG02, yes I think they where originally, but they had already been painted over (black!) when I got them, they were around 30 years old.
I'm with slammin about the lack of oxygen promoting corrosion or oxidization. I had an aluminium dagger case that has been powderecoated, again by a previous owner.
The aluminium would blister behind the powercoat, and looked to actually promote corrosion.
Once this coating was removed, it helped slow any further pitting.
My masts are well over thirty years old anodised and weathered and the wire halyards flogging
the masts plus any chips and scratches have corrosion last time I looked
Think I'll wait and re appraise
Need to drop into the riggers any way
I scrubbed off all the paint and welded up corroded/unwanted holes in this mast 12months ago.
I bought Norglass all surface metal primer"no rust" and Norglass Northane polyurethane 2 pack paint for it but soon after I had removed the paint I decided I will just polish it and leave it bare.
I rejuvenated my cavalier 32 mast and boom last year,using Nyalic
so far so good
great stuff,easy to apply,but careful preparation needed.
happy to discuss further if interested
Select to expand quotescaramouche said..
I rejuvenated my cavalier 32 mast and boom last year,using Nyalic
so far so good
great stuff,easy to apply,but careful preparation needed.
happy to discuss further if interested
Yes I'd appreciate a little bit of info. Assuming your mast was already stripped of paint, can you say a sentence or two on the prep you had to do?
After the prep, did you brush, roll of spray the Nyalic on? How many coats, and how many litres of Nyalic (and cost/litre)?
Thanks
Just a couple of facts about aluminium:
It oxidises very easily, but luckily the oxide layer is produces, cuts of the oxygen so no further corrosion occurs. This layer of oxide does not stand up to wear and rubbing.
Anodising is just a electrolytic process to thicken the oxide layer, thus providing a greater protection. It also provides a better adhesion for paint or epoxy application which is needed in high wear situations.
So most masts are anodised, and then coated (a lot of times it is a clear coating). So in restoring...it best to keep what anodising is there intact, key the surface as it probably has some coating on it. Then coat with a high wear resistant coating, epoxy probably - but there are others.
For a metal paint I would suggest the stuff Aldi sells. $7 a litre, terrible fumes. Goes over bare aluminium fine. Not many choices of colour and when its on special you may have to fight off the pensioners. Made in Germany.
Select to expand quotescaramouche said..
I rejuvenated my cavalier 32 mast and boom last year,using Nyalic
so far so good
great stuff,easy to apply,but careful preparation needed.
happy to discuss further if interested
Would like some more info when you have the time scaramouche
Mast stripped physically and slowly with angle grinder with abrasive
then washed with detergent,then bicatb,dried and painted with brush/roller
painting the easy part
would use chemical stripper next time
nyalic offers great advice,personal service on phone too
strongly recommended
Select to expand quotescaramouche said..
Mast stripped physically and slowly with angle grinder with abrasive
then washed with detergent,then bicatb,dried and painted with brush/roller
painting the easy part
would use chemical stripper next time
nyalic offers great advice,personal service on phone too
strongly recommended
Not sure what sort of chemical stripper you can buy for Anodize mast.
What I had in mind was much the same as you have done . Mainly rough up the mast surface for the paint primer to adhere to . clean up the corrosion surfaces and prime it well
.
I first went down the chemical stripper path to remove paint from my mast. Looking at products they use in the aircraft industry, trying to steer away from caustic products. But hell, I figured for a 40ft spar, I could spend 50 bucks at Bunning's for some stripper style disks for my 4 1/2" angle grinder and with a days work, I could pretty much have the job stuffed, so that's what I did.
I do a bit of anodizing at home, just stuff for speedway cars and aluminum things that need a tougher coating. For an off the shelf product, nothing strips anodizing faster than sodium hydroxide or in hardware language "caustic soda" If you want to remove paint and not aluminum, sodium hydroxide products should be avoided. But I do wonder how much aluminum I removed in the scrubbing process . I guess I should have weighed the mast first
In some way those Wattyl Kill rust epoxy gloss enamel spray cans sounds simple solution once its prepped etched and primed . Then when needed you could touch it up with a spray can
I have done a few sabre booms with Nyalic. Rationale being to keep them as stiff as possible.
Reality is the Nyalic does need to be re-finished every 3 to5 years. Luckily it is a quick and simple process of a good wash, rub back with 800-1000 grit where necessary and re-spray.
I have been using the spray cans, are ridiculously expensive but get a better finish than the foam roller.
