Mast paint yes/no?

[slug]

Originally Posted by belizesailor

...and Tefgel the screws/fastners to isolate from aluminum. I cut isolating pads from plastic packaging and place between the hardware and the mast.

Careful with tefgel ...it works so well that fastenings subject to load cycles will work loose
The same company the makes tefgel also makes a product called tuffgel
This compound actS like a thread locker . Breakaway torque 1.7 Num

It is more appropriate for many rigging applications



https://www.tefgel.com/contain.php?param=tuffgel_infor

[noelex 77]

I have been asked by a member to add a poll to this thread to determine if the consensus is a painted or unpainted mast.

[a64pilot]

OK, let me explain why it’s not as simple as a yes no answer, and why aircraft aluminum has a bearing on it.
First I believe Most production masts will be a 6061 extrusion, which is an aircraft aluminum.
My bet is that most masts are anodized, and if so then as long as you don’t remove the anodization during the paint prep you will most likely have success with a painted mast that the paint will last, not because of the paint, but because of the anodizing preventing corrosion from occurring under the paint.
But if you left it alone, Unpainted, you would have no problem either.

If for whatever reason you really have a bare metal mast, something that I have never seen, but there are millions of masts that I haven’t seen so there may be many out there, but if you have a bare aluminum 6061 extrusion you will not have good luck with any form of paint, including powder coat. You need a corrosion preventative layer under the paint, anodize is best, it’s an electrical process that plates if you will a chromate layer on the aluminum.
However you likely can’t get a mast anodized, this brings us to alodine, which is a chemical process that puts a chromate layer on the bare aluminum, not as good as anodized as it’s soft compared to the hard coat of anodizing, but you don’t need a mast length tank to alodine, you can do that on a table with a brush, plus it’s a good prep adhesion wise for paint, but don’t try to paint bare 6000 series aluminum, the paint layer will likely fail if you try

If you paint bare 6061, you will most certainly get corrosion under the paint and it will bubble up and come off, this isn’t paint failure, it’s corrosion under the paint.

Post number 16 on this thread Delancey explains it well
http://www.cruisersforum.com/forums/...-120880-2.html

[belizesailor]

Good to know. I got a couple of big tubes with a new roller furler last year, will verify which product.

[slug]

Originally Posted by belizesailor

Good to know. I got a couple of big tubes with a new roller furler last year, will verify which product.

When tuffgel is not available I see pro riggers using a product by loctite

I can’t remember it’s part number

It’s a white thread lubricant , thread locker used for plumbing fittings

[jamhass]

Originally Posted by belizesailor

...and Tefgel the screws/fastners to isolate from aluminum. I cut isolating pads from plastic packaging and place between the hardware and the mast.

Right on, and a couple of additional thoughts, applicable to either painted or unpainted masts.

1. There are some very nice inexpensive thin cutting sheets (sold at Walmart, Amazon, etc) that make great isolation pads, and are often easier to work with than packaging material because they are flat to begin with. Here is one example
https://www.amazon.com/dp/B01M2XFGVK..._t2_B019PKEBPU


2. There is a gas-line PVC tape (sold at Home Depot, etc. to wrap gas lines where they come out of the ground.) This is similar to electrical tape but quite thick and more adhesive. It is really easy to stick to the backsides of fittings, trim with a sharp knife and serves as an excellent barrier to corrosion.
https://www.homedepot.com/p/2-in-x-5...E&gclsrc=aw.ds


3. I've had great luck with Tefgel.

4. Loctite recommend Loctite blue for marine applications

[Cpt Pat]

I use Bed-it butyl tape for electrical isolation (and for bedding other hardware) which also achieves a water-tight seal. It's far more flexible and resilient than any adhesive like 5200. It keeps water out of the joint that contributes to corrosion under the joint. It conforms well to a slight camber, like the surface of a mast.

Over apply it, squeeze the part in place until snug, come back a day or two later and finish torquing up the fasteners, and use an exacto blade to trim away the excess around the edges.

I've pulled bedded parts off a surface (a hard thing to do with 5200) years later and seen no degradation of the bedding tape. It's so resilient that it's like pulling taffy apart after years in service.

[thereefgeek]

We cut & shortened our boom a couple years ago and had some welding done on the reefing and outhaul sheave box. I had to strip some paint anyway for the welding, and and ended up stripping the whole thing because we liked the look. We clear-coated the boom after meticulous surface prep, and plan on doing the same to the mast the next time we haul out and pull the stick.

Aluminum always seems to oxidize around fittings and hardware no matter how well you prep & prime for paint, or use Tef-Gel on hardware. A lacquer-based clear-coat is way easier to “touch up” than a 2-part LPU paint.

https://m.youtube.com/watch?v=q8-lkBKAlc8&t=90s

[slug]

Originally Posted by jamhass

Right on, and a couple of additional thoughts, applicable to either painted or unpainted masts.

1. There are some very nice inexpensive thin cutting sheets (sold at Walmart, Amazon, etc) that make great isolation pads, and are often easier to work with than packaging material because they are flat to begin with. Here is one example
https://www.amazon.com/dp/B01M2XFGVK..._t2_B019PKEBPU


2. There is a gas-line PVC tape (sold at Home Depot, etc. to wrap gas lines where they come out of the ground.) This is similar to electrical tape but quite thick and more adhesive. It is really easy to stick to the backsides of fittings, trim with a sharp knife and serves as an excellent barrier to corrosion.
https://www.homedepot.com/p/2-in-x-5...E&gclsrc=aw.ds


3. I've had great luck with Tefgel.

4. Loctite recommend Loctite blue for marine applications

Another way to isolate stainless fittings from the mast Is epoxy

Paint the back of the fitting with epoxy Let cure. Then install

Always use a bedding compound to prevent water intrusion into the joint

[slug]

Originally Posted by Cpt Pat

I use Bed-it butyl tape for electrical isolation (and for bedding other hardware) which also achieves a water-tight seal. It's far more flexible and resilient than any adhesive like 5200. It keeps water out of the joint that contributes to corrosion under the joint. It conforms well to a slight camber, like the surface of a mast.

Over apply it, squeeze the part in place until snug, come back a day or two later and finish torquing up the fasteners, and use an exacto blade to trim away the excess around the edges.

I've pulled bedded parts off a surface (a hard thing to do with 5200) years later and seen no degradation of the bedding tape. It's so resilient that it's like pulling taffy apart after years in service.

5200 is not a bedding compound ... it is a structural adhesive

https://multimedia.3m.com/mws/media/811831O/3mtm-adhesive-sealant-brochure.pdf

The common 3m bedding compound is 4200

[MJH]

Originally Posted by jtsailjt

I have a friend who just bought a boat with an aluminum painted mast. There is some bubbling of paint around some of the fittings but overall the mast looks great and the step and bottom of the mast are fine. The quote he got to remove all the mast hardware and repaint is a good deal higher than he wants to spend. I've never liked the idea of painting aluminum because it always seems to have problems with adhesion or eventually water gets behind it in places (around fittings) and is held in place by the paint so corrosion/bubbling occurs.

So, would it be acceptable for him to have his mast sand blasted with the hardware in place and just leave it as bare aluminum or would doing that invite further corrosion? Does aluminum need to be protected by anodizing or painting or is it OK to leave it bare? I've always had masts that were bare or anodized aluminum and have never had any problems with them. Other than for aesthetics, is there any reason to paint an aluminum mast?

Aluminum masts should not be painted. Once painted the owner has a lifetime project of keeping it up...I speak from experience.

My new-to-me boat came with a keel-stepped painted mast, all 63' of it end-to-end. The mast paint wasn't in good shape and the mast had been removed and stowed for shipping with the boat, so it was an opportune time to paint it before install.

I wanted to do the job right and was diligent in seeking professional assistance before undertaking such a job for the first time. I spoke with an Interlux representative and got details on the correct preparation which I know is the most important step, as I have painted cars before, and used Interlux Perfection, a two-part polyurethane. I followed his directions to the letter and got it done. Within a couple years the paint started to peel above the deck but not below in the salon. I wish the previous owner had never painted it.

FWIW I feel the same way about painting fiberglass hulls and decks. Yes, my boat has those painted as well and I recognize the lifelong commitment require when the original fiberglass has been breeched...it only takes one season for that newly painted look to disappear. I wish they never had been painted. It is a temporary measure for aesthetic purposes only.

My previous boat was 28 years old when I sold it. It had the original aluminum mast, deck, and hull finish and looked great because I took care of it. Painting is the lazy way to maintain a boat surface and should be left as the very last resort for one reason alone...there is no turning back.

Good Luck,

~ ~ _/) ~ ~ MJH

[Martkimwat]

I think you will find even small boat masts are anodised, I've not seen one that isn't certainly not here in the UK. Painting masts seems to more of a North American thing, although there is nothing wrong with it so long as it is done properly. There are now proprietary products to allow the paint to adhere to bare metal instead of using an etch primer which is a pain to use. International paints do a clear primer that is almost as thin as water. it leaves a very thin film which is slightly flexible which allows for movement. You then put two coats of two-pack epoxy primer followed by two coats of two-pack polyurethane top coat. I did it to my mast which looked unsightly due to scratching of the anodising. Did not need to sand off the anodising which would have been the case with etch primer. I stripped all the fittings and did the job with a spray gun then re-bedded the fittings using Tef-gel which is used in the aviation industry to isolate different metals. Still looks good after five years. with no lifting of the paint.

[thinwater]

I've had 3 unpainted and 1 painted. Painted required maintenance, the others were more trouble free. Yes, you can get corrosion around a fitting, but it's worse on a painted mast, because localized paint failures concentrate the galvanic corrosion.

If you have a painted mast, you maintain it. Certainly not worth stripping and it can be maintained. If it is unpainted, for heaven's sake, leave it that way.


IMO, things that work well look good.

[Ambler]

I like the look of an Aluminium mast unpainted so I stripped all the fittings off while the mast was out on trestles. I then sanded the paint off back to bare metal, etched the aluminium with an acid designed to remove any oxidisation of aluminium, then washed it off with water. I then applied a product called NYALIC which is a clear liquid that effectively gets right in to the metal and seals it from corrosion in the future. I was told it was developed during the space program and is almost as effective as anodizing.

I did that 15 years ago and haven't touched it since. A 500 mililitre bottle goes a long way and I still have about 150 mils after doing the mast, replacing the boom with a new spar 8 years ago and applying the NYALIC to that.

My local spar builder uses it too.

[Paul Howard]

I had a bare, non-anodised mast on a boat that I did a circumnavigation of the world on, then another family did the same and no problems with the mast. I did wax it with a good quality automotive paste wax at least once a year and had no pitting or discolouration where parts rubbed.