Carbon/graphite, Kevlar or Glass

PAR,

What makes socks hard to work with? I have done the peel ply, mash down method 5-6 times, and each time found it a total pain.

The Chinese finger puzzle deal looks like it would be a total slam dunk, but expensive for sure.

Thanks in advance for your opinion.

Allan

 

I had forgotten about the socks...and last night thought about trying one, doing it this way and wondered if anyone has tried it...seems easier than blending tapes...

Cut section to length...factoring reduction or stretching of diameter to length.

Mix small batch of epoxy

Dip each end of sock (properly held apart by a piece of PVC) into mix and cure, so ends do not unravel.

Roll up each tube as one rolls up sock and fit to wet mandrel or in my case mast and unroll.

Rewet and set sock to mandrel diameter and wrap with either peelply or perf...depending on finish choice.

May use epoxy/hardener combos from outfit called Aircraft Spruce.

Seems, in the mind, easier than applying separate tapes...and not much more expensive, particularly if it works and the seamless finished product does serve its intended purpose.

 

Sand the original until all the gloss is gone, and room temp epoxy will stick, no problem. Carbon loses a lot of stiffness if it is not aligned with the loads. Therefore a spiral will not stiffen the mast, nor will a braided sock, although both will add torque resistance. To reduce bending, run the carbon vertically, equal amounts on each face. Then add a layer of light glass or a sock over it at +/-45 degrees. Consolidate firmly with vac bag, bicycle inner tube, heat shrink tape or bag or strips of peel ply or packaging tape, sticky side out. Be very careful with the last 2 as they tend to push the unis out of alignment.

rob

 

Thank-you, Rob. I ordered a short sock Sat, to add to the top section. My thinking was the mast has no fore-aft orientation. If not stiff enough, may have to add glass to one side, and mark it. Am trying to avoid adding glass to the fairly stiff bottom section. Mast is all graphite model by North.

 

Glass has very low stiffness, you will be wasting it on a carbon mast. Add lengthwise uni carbon all the way round where you want it stiffer, then put the sock over it and smooth it as well as you can if you don't want to wrap it.

rob

 

Yes, the glass would have been a waste and added weight to no good affect.

Rob, was thinking to go in reverse, sock first, to blend close to original and some uni added where more stiffness is needed. No vacuum...just peelply tightly wrapped or packing tape.

I have no way to determine finished product, save by trial...and adding as needed. I am hoping the sock will be sufficient as the mast is bendy at the top mostly and where the sock is going...

 

One of the ways carbon fails is it gets out of column under compression, same as if you press on the ends of a bundle of straws, they pop out sideways. Putting the sleeve over the unis would prevent this. It would also make it easier to compress the laminate. Wrapping unis can cause them to twist.

The sock will add very little stiffness on it's own.

rob

 

I see. Will do the uni first and mark it so it will be forward...

 

windsurfer mast for sailboat?

New to the forum, I just found a 5/16/12 post from messabout, mentioning how to stiffen a graphite windsurf mast for 60 sf. small boat sail. Uncanny that messabout also mentions reinforcement for sprit boom snotter. Quoting messabout:

"Yeah I know that the combination of modern mast and nineteenth century sail was/is incongruent....It works however."

My thoughts exactly for a leg o'mutton sail on a small Cedar Keys sharpie. Question: how to reinforce the stick at the foot, at the deck and at the peak to take a halyard block. Also how to reinforce for cleats? I am assuming this rig can stand unstayed?

 

Kewl...I grabbed the horns and ran with it...bought three cracked at base surfer masts and combined with T6 with wood ferrules.

Then I sleeved, guessing a bit on stiffness...voila, the first one needed a bit of smoothing...my bad...but added to matching base for Kite dinghy and sleeved sails, works perfect.

In fact, worked so well, I did same with spars for the boat shown below, which is about a week from wet.


Spar is half long carbon surfer mast, sleeved to stiffen, plus 10 T6 base...and boom is 13 feet repaired carbon plus 3 feet of T6 at gooseneck...expect similar results...

 

Hey BobBill: Thanks for the post. Could you elaborate on "T6 with wood ferrules?" Also, more on how you "sleeved to stiffen, plus T6 base...and boom is 13 feet." Be well.

 

Sure. Keep in mind, have refurbed a few boats, but the carbon and glass
sleeves are novel to me and I have relied on wonderful advice and patience here from Par, Steve Clark, Epoxymoron, Major Tom, Lord Chris Ostland, Upchurch, Brian Eiland, Petros, Flados, Tom Speer and others which my beer soaked mind cannot dredge up at the moment.

You can buy socks in glass or Carbon from a number of sources, I used Fibreglast for carbon and glass socks from Duckworks, sources putting up good help...which I need much of.

The socks are like Chinese finger thingys, you push ends in and diameter widens, pull out, narrows...but not so easy to deal with without practice...

BTW, I used zip-ties on ends to draw tight along length, and taped ends over peel ply using masking tape...the peel ply needs twisting too, so be certain to wear decent rubber gloves...



So, the carbon stiffened the carbon surfer masts...base cracked, cut off and sock went over.

Problem I had was novice...I lathered up mast after putting on copper water pipe to keep level...then began adding sock...PIA and time consuming.

Second try I added sock and stretched tight then tied ends to keep in place, applied the epoxy and then wrapped with peel-ply tape I bought from Aircraft Spruce...more PIA as edges of the PP frays and need to keep cutting off...but, while I hate PP, you need it to be sure the sock stays in contact with carbon tube, especially at ends where glass tends to float off the tube...maybe better way, but it is what I did...FWIW.

I am not sure how it worked out, as the alternate mast turned out perfect, though a hair rough looking, under sleeve...screw it.

Okay, second boat is based on Malibu Outrigger and has a long spar and 16' boom. I used a 10-foot piece of 6061 T6 AL 2-inch tube with .065 walls as I recall. Originally had .125 wall tubes (too heavy) the AL tubes join with carbon surfer masts I sleeved (carbon).

I used a wood ferrule insert to join...had a fellow turn to dia I guessed at and added carbon sock and glass sock over that to insulate from carbon...but then the new tubes had greater ID, so I had to add three layers to dowels (old kiln dryed 2x4s epoxied together with glass and turned...

Dowel ferrules fit the carbon spars but a bit large for the T6, so I have to sand a bit and fit...have not done it...raining here and dealing with other stuff on boat...

I figure to keep the carbon/T6 section separate and join when using...pinning with monel nails, screws or something...not worked it out completely.

BTW, the base of the spar and the boom at gooseneck also have these dowel inserts with SS tubes to slide on to goose neck..., and glass sock to keep carbon from T6 AL.

I used to craft glass fishing rods and figure the ferrules as same but bigger. Carbon is very tough stuff...I hope, and if I did the socks right...

Pics will add to help explain and some may be up later...on phone and other computer...have to figure out how to get from phone to computer to here...might be a day or so. Beer time.

Hope this helps and if someone has critique, or flame, feel free, I can handle it ... never had a clue I would have to nearly craft everything from scratch...but in for penny, in for pound...2 old Hobie hulls resurrected and if this thing sails well, be a smile on my puss and beers in belly...love me back boyos...

Pic is planned/design...will put up some more later.

 

Carbon Surfer masts to Aluminum Ferrules

I must have trashed a couple pics cause I cannot find them now, but you never know...I have three cameras...


Here are a couple pics that should help...

 

Hi BobBill good to see you are still at it and still sharing your ideas here.
After commenting on this thread a couple of years ago I reinforced an old Carbon mast tip to use as a bowsprit for an asymmetric spinnaker. I used unis lengthways and a biax sock to hold it all together. Wet out each subsequent layer before applying cloth. To apply the sock i pulled a premeasured length over a tube that was just big enough for the sprit to pass through. Then i carefully slipped the sock off the tube onto the resin wet spar. I did this progressively which allowed time to smooth it out and get the cloth weave aligned neatly and completed wetting out of the sock as i went.
Afterwards i wrapped in peel ply and vacuum bagged it during cure.
the spar would be about 6' long and tapered down from 2.5"

I would think using a tube like this would work for longer spars also if you want the sock.

 

JRD, excellent...I roughed it and sanded later. I should have done as you did, but I did not have the room and no vacuum system which is best...

I just put sock on spars separately and wetted later, as the first one that I wetted out first was a nightmare to get on the spar...

After I smoothed with sander...the first one worked well, and is a bit rough but luff under sleeve...have not sailed with others yet.

I am going to do a sprit also and will do your way - sort of move the "Chinese squeeze" sock from pipe to spar, but no vacuum. Then wrap with peel ply (miserable job) and twist tight and tape etc, and hope, of course.

I figure this for next season...still not wet, but maybe next week, I can find a decent, plain main (no bolt ropes, no roach, no headboard) but it seems simple is not in most loft's repertoires.

Thanks for help.