Carbon Fibre Mast Rash

[BobT]

Hi All,
Compared to others carbon fibre masts my BRe's appears rather dull and furry. Not too much of an issue apart from the fact every time a brush against the mast when rigging or de-rigging I  run the risk of getting a rash or small fibre splinters.  Is there anything I can do to coat the mast to prevent this.
Regards,
Bob

[Peter Taylor]

Hi Bob,
I assume its UV degradation. You can paint the mast and I've been told it's advisable to do so; indeed Matt said more or less just that at Mylor last year. My mast is a bit fuzzy too but so far I've been too lazy to do anything about it. Hopefully the degradation is not too deep!  My carbon fibre dinghy mast from John Claridge Boats was painted white from the outset and has weathered much better.
Peter

[mark1]

any suggestion of what kind of paint works best?

[Rob Johnstone]

Hi Bob,

I had a tip from a motor panel beater the other day about how to deal with the fraying ends of kevlar and carbon fibre. It sounds a bit drastic and I have not tried it out and take NO RESPONSIBILITY for any damage caused by adopting this technique!

Souse them with lighter fuel (a small area at a time) and light them. The fibres apparently act like wicks and burn off.

Well, I said it was drastic.

[Peter Taylor]

any suggestion of what kind of paint works best?

From Swallow Yachts via Lara: You can use any good quality 2-pack marine wood varnish but if you're going to go to the trouble of applying a product then you'd be better off using a 2 pack paint such as International Perfection or Epifanes as it's just much better protection for the mast and you won't need to reapply it each year as you would do with a varnish.

Peter

[BobT]

Hi All,

Since I first posed the question Swallow Yachts have confirmed it is likely to be UV degradation and gave me the same advice as they did to Peter in an earlier post.  I then started poking around on the web and found this link:
 
https://www.boatpaint.co.uk/acatalog/datasheets/International/Extras/International_Manuals/Perfection%20Application%20Manual_GBR_ENG.pdf

Which suggests when working with 2 part paint, not only do you need the paint but two types of primer and possibly one filler (not for my mast I hope).

Swallow Yachts also mentioned varnishing the mast but that this is likely to become an annual event.

I did some further web searching (hesitate to call it research). All the sites I have looked at talk about sanding down the mast to remove the "loose" fibres with lots of water and gloves (carbon fibre appears to be nasty stuff when not contained by resin). None mentioned burning them off so I think I will leave that for another day!  The need for a good surface for whatever finish was also mentioned a lot. There was then talk of various paints and varnishes from Halfords Clear Lacquer all through to 2 pack paint being regarded as the best but not easy to put on well as it can have quite a long tacky phase when drying so the chance of picking up dust is increased.

Bottom line would appear to be if you want a proper job, use 2 part paint, if you just want a quick fix then almost anything will do for a year.

If anyone has used 2 pack paint could they spread some light on the preparation and use of primers and fillers before the "top coat".

Bob

[TimLM]

Hi Bob, the lengthy preparation recommended by International isn't necessary on a carbon/epoxy mast. Rubbing down is a nightmare and much better avoided. Clean with acetone (wearing gloves) on a cloth with light strokes, let dry and then give at least 2 coats of 2 pack not to thickly applied. At 25 deg C it will be touch dry after about 20 to 40 min. Follow the re-coating times on the can - a beautiful finish.

Tim BRe Papagena

[Michael Rogers]

It's possibly worth mentioning that two-pack paint won't go on top of traditional one-pack. Therefore a 'quick fix' with one-pack now with a view to doing something more long-lasting with two-pack later won't work - it really won't!

In my experience, two-pack is worth the (considerable) extra effort needed to apply it properly. There is no comparison in terms of durability.

[BobT]

Two pack/part on order will let you know how it goes. Thanks all for your input.
Bob

[BobT]

Mast now painted with two coats two pack and looking shinny.

First photo - Mast before.
Second photo - The amount of "fur" that came off with light sanding (240 grit wet).
Third photo - After first coat (applied with brush).
Fourth photo - Finished, well almost.

This was all done outside in garden on reasonably windy days which was not ideal and the finish has plenty of minor imperfections; insects, pollen, dust. However the aim was to stop getting a rash every time I brushed up against the mast and I think that has been achieved. Two coats may not have been necessary but that is what the instructions wanted.  The paint went much, much further than I thought so wasted a fair bit. Although used masking tape where necessary the photos show quite a lot of seeping even though I rubbed the tape in place. It does scrape off reasonably easily, just need to do it!

Regards,
Bob

[tcave]

I followed this advice with great results. Mast looked like new, beautifully shiny. However it was a bit cooler for the fourth coat and some parts of the mast went a bit dull.

“ From Swallow Yachts via Lara: You can use any good quality 2-pack marine wood varnish but if you're going to go to the trouble of applying a product then you'd be better off using a 2 pack paint such as International Perfection or Epifanes as it's just much better protection for the mast and you won't need to reapply it each year as you would do with a varnish.”

[Julian Merson]

Agreed.  I also found that post really useful, and, during the first lockdown this time last year, painted my mast with two coats of two-pack International Perfection.  The process was remarkably straight forward - my first foray into two-pack painting.  Very little preparation necessary; just a bit of sanding down and cleaning.  The results have been really good - 12 months later, still looking excellent with no damage and, more importantly, no further instances of 'mast rash'.  (It occurred to me that, if splinters can so easily cause annoyance to the skin, who knows whether further splinters might become airborne, and mess with the lungs...)
I took some photos - both 'before' and 'after' - in this blog entry: https://daisyiii.blogspot.com/2020/05/maintenance-and-modifications-during.html

[TimLM]

Lovely mast Bob, and nicely painted/varnished.
I painted all 11 of my carbon spars with 2 pack but white. It turns out to be harder wearing than the epoxy resin or the polyester varnish spars come with today. With the gaff running up and down the mast then swinging on it it does need to be tough and so it has proved to be, only little touching up this year after 3 hard years sailing!

[Sea Simon]

“ From Swallow Yachts via Lara: You can use any good quality 2-pack marine wood varnish but if you're going to go to the trouble of applying a product then you'd be better off using a 2 pack paint such as International Perfection or Epifanes as it's just much better protection for the mast and you won't need to reapply it each year as you would do with a varnish.”

Can anyone illuminate as to why two pack paint is so much better than two pack varnish?
...or am I misunderstanding?