Care of Carbon Masts
The following is answers Christian posted in response to questions.
Can a carbon mast last as long as aluminum masts. Like a 30 year old Ensign mast?
There are 30 year old carbon masts around. What is required for them to last is that you have to keep UV from breaking down the resin matrix (what you would notice by the resin turning yellow and chalky).
This can be achieved by a good coating of the spar and obviously patching it if the coating flakes off. The Viper sticks are clear-coated – am unsure which brand of clear-coat but am 99 sure it has an UV-filter in it. My preference for clear-coat is Awlgrip as it has a very good UV filter – BUT – not as good as a colored coating, which has better UV filtering properties. Ideally a light color so the stick doesn’t bake too much which could be tough on spars, which have not been cured at high temperature – essentially you want the carbon to never reach a temperature close to the curing temperature. Not a problem for autoclaved carbon structures but can be a problem for low-temp cured carbon structures. I am very confident that the temp is not an issue for the Viper sticks.
Obviously; carbon sticks are not too fond of scratches, that go through the carbon strands themselves. I fly fish a lot and have a number of high end; high modulus carbon rods – the wall thickness at the tip is measured in tenth of millimeters and sure – if you get a scratch that goes halfway through the carbon – it will break. But, if well cared for they are the most durable kind of fly-rods available – alu (and I even have one of those) do not even come close in terms of longeviety despite a weight 4-5 times higher than the carbon rods. Carcon rod blanks for pretty heavy duty saltwater flyfishing are something like 2 ounces for a 10 foot rod, that will handle 30-40 pound stripers.
Your reference to ensign alu sticks – have you ever tried to move one of those around? They are heavy as shit, which is also why they are somewhat un-tunable – i.e. you cannot put any bend in them at all – it would tear the boat apart if you try applying enough rig tension to bend them – it would probably end up looking like a banana split with a stick in the middle (which is still not bent). Such a completely overbuilt alu stick will last forever (or at least as long as corrosion hasn’t taken over) as the loads on it are miniscule compared to the stick. If you have a lightweight alu stick (engineered to just be strong enough) it would be a whole other kettle of fish as you would encounter metal fatigue easily much earlier than a carbon stick. Carbon is much better at load cycling than any metal available as long as the resin matrix is not compromised – hence the need for some level of maintenance.
So you’re saying that if something metal clanks against the mast, it’s not going to fracture, and the clear coat provides some protection from scratches, but don’t sharpen a knife on it. What I also gather is that it’s best that the mast not sit all summer every summer in the Florida sun and that every year, the mast should be inspected and patched with a proper clear coat. I also wonder if the rig should be eased off when the boat is being put away for a week or two?
Something metal clanking against the mast does have some impact as it could shatter the resin (if it is big enough it could shatter the carbon too) but it does need to be somewhat of a big impact to have substantial damaging effect – don’t start chopping away at your carbon stick with an axe. You would be surprised how impact resistant carbon is. On my Viper 830 i have carbon shrouds and I have gotten pretty detailed descriptions of the impact testing done on this kind of rigging – to make sure it will withstand free-flying spin poles etc. many repeated blows with some good force behind it. Blunt force trauma (to put it in a CSI kind of terminology) will be most likely to shatter the resin matrix rather than the carbon strands. that being said – if the resin is shattered, the carbon is suceptible to failure as the stretch resistance will be unaltered but if the resing is not there to keep the very thin strands in column they will buckle easily) – essentially think of the carbon fiber strands as lines on the boat – the lines will take a lot of load in tension but is damn tough to push anything with unless they are kept perfectly in column. Something with a sharp edge will have a bigger impact as the force applied will be concentrated in a very little area. And don’t sharpen your knife on it either…………….
If yor mast sits in bright sunlight, the UV coating will break down faster – so if you leave your boat for weeks on end without sailing it – take the stick down and put it in a mast bag (light materials with good UV protection is the best as it will keep the mast from overheating while protecting it from UV) – kinds like the human body, which likes being sheltered from UV and kept at a resonable temperature). If you have a shed or somewhere else shaded – hang the mast there.
Unloading the rigging a bit is always a good idea if the boat sits for a while – probably has a bigger beneficial impact on the hull than the stick though……..
Definitely inspect the mast at least every year – actually every time you take the stick down anyway (but at least once a year) – give it a look-see and take care of any dings, scratches and peeling. For a quick fix until you do a proper repair (if the clearcoat is peeling) give it a quick squirt with Krylon – not phenomenal UV protection but better than nothing. Awlgrip is definitely preferable but it is a PITA to use as it is a 3 component urethane (you gotta’ mix 3 ingredients in the right proportions, which is tough for a tiny batch) – it does flow very nicely though and you can get a finish almost impossible to discern from a spray job as long as you follow the instructions to a T and paint it so it can at least surface cure before the evening dew sets in. What I do with my carbon components is patching up if i have any peeled clearcoat and when i have more patches than I would like, I re-do the whole stick. Don’t wait until it gets real bad as you would then have to sand off all the old clearcoat and re-coat with 5-7 coats. if you catch it early you can just do a light sand, clean it off well with acetone followed by a special cleaner and one or two coats of Awlgrip (with no sanding in between if you do the second coat at jusst the right time.
BTW – Jamestown Distributors will ship Awlgrip without charging more in Hazmat fees than the cost of the paint.
Good Luck. Christian.