Author Topic: Naish Javelin- top rail redo, layering questions  (Read 3825 times)

cruzanboard

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Naish Javelin- top rail redo, layering questions
« on: April 13, 2016, 10:47:19 AM »
I have removed the raised top rail of an older Javelin. See pics.
(its an experiment to use vacuum bagging for first time, and I don't like the raised rail.)
Wondering on layering for the deck, rail, and sides.
I have a 4" carbon tape but doesn't cover the full work area.
Thinking of the following . . .
Deck (with wood laminate removed at work area) - double 6 oz. glass or 6 & 4 oz. glass.
Rail - 4 oz. glass under with 4" carbon tape on top.
Sides- double 4 oz. glass.

Comments appreciated. Thanks.

PonoBill

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Re: Naish Javelin- top rail redo, layering questions
« Reply #1 on: April 13, 2016, 12:09:40 PM »
The schedule you suggest is going to be heavy, even with table prepreg and vacuum bagging. You'd be better off peeling the top since you're doing the upper rails. anything you do to make the rails strong enough and integrated to the deck is bound to have substantial overlap. You don't need a huge overlap if you use carbon, but it does need to lap onto any existing structure to give full strength. Boeing says 1" is sufficient, but I'd use two, so your carbon tape isn't going to work. You'll want some glass over it to reduce the amount of hotcoat seeping, and for that it makes sense to do full width. If you're committed to this course I'd spackle the exposed EPS, do one layer of 6oz carbon table prepregged, then 4oz s glass. Hot coat only the rails with a few inches overlap onto the deck and sides. And start doing some curls, you're going to need some arm strength. Oh, and don't step on those rails much, and don't set the board down bottom up on gravel.

I don't know what you mean by "wood laminate removed at the work area". Are you talking about stripping the deck?

I'm a recent convert to minimal layers, so I'm still working through the bugs, but you've got the heel dent issue covered if you leave the deck alone, so keep everything else thin.

I've found through painful experience that first time vacuum bagging is best done with smaller things. Lots to learn. Doing something little teaches you what not to do without all the  vacuum leaks, rushing, and layer issues you'll encounter. Most of my early vacuum bagging efforts resulted in a wad of expensive s-glass or carbon out in the driveway, smoking gently as it turned into abstract art.
« Last Edit: April 13, 2016, 12:26:53 PM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

cruzanboard

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Re: Naish Javelin- top rail redo, layering questions
« Reply #2 on: April 13, 2016, 05:49:55 PM »
Thanks PB for the reply.

I have spackled the EPS, and have about 1" for the tapers.
The Naish had a wood laminate on the deck under the deck pad area and wrapped around the raised rail a bit.
It all got removed as part of the 'flattening' of the deck. Kept the rest of the deck in place.  So I figure I need to support the outside portions of the deck with more glass or carbon where I removed the laminate.

When I cut off the raised rail, I was surprised by the thickness. Looked like several layers of glass (or some kind of poly-composite. And then just a thin layer of carbon on the top.  Made the carbon look like it was more decorative than structural.

Regarding the vacuum bagging, I am beginning to think I have first time on the project without practice is not a good idea. But Ive gotten impatient with the project and want to get the board back on the water. May just do a wet layup and move on with it.

SUPflorida

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Re: Naish Javelin- top rail redo, layering questions
« Reply #3 on: April 13, 2016, 06:31:20 PM »
Curious...What was your motivation for re-working the rails?

cruzanboard

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Re: Naish Javelin- top rail redo, layering questions
« Reply #4 on: April 13, 2016, 07:05:20 PM »
I am not a fan of the sunken decks. At least the deep ones like the Starboard boards you can wedge your feet against the sides and get some stability. The mild raised rails on the Naish boards don't do much IMHO, and keep me from sliding my feet out and wrapping my toes around the rail if needed, like a sup-surf board.
I use this board for flat water only so the decreased freeboard doesn't matter.

Plus, it became an excuse to learn how to vacuum bag, but now may not do it per PB's comments.
Oh well.

supuk

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Re: Naish Javelin- top rail redo, layering questions
« Reply #5 on: April 13, 2016, 11:27:50 PM »
Normally I would have about 24oz of glass on a board in that area perhaps use a little more as you replaceing a wood sandwich, Naish used to use a polester cloth it was a pain to work with. I probably wouldn't worry too much about the carbon make sure you get it filled and looking perfect with spakle or microbaloons before you start glassing, feather the paint back further then starting with the widest pice and staggering in each layer by about a inch do at least 5 layers of 6 oz starting with 3-4 inch over lap. May be do two or three first give it a sand then two more the last one will act as something you can sand into without worrying, hot coat but don't go over any paint then sand and spray ect keep it simple and you probably won't add any significant weight.


cruzanboard

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Re: Naish Javelin- top rail redo, layering questions
« Reply #6 on: April 14, 2016, 09:58:24 AM »
Thanks supuk. That's the layering input I was looking for. So a wet hand job for me. No vacuum bag.
Hey, Ive got some 4" carbon tape for sale. :D

supuk

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Re: Naish Javelin- top rail redo, layering questions
« Reply #7 on: April 14, 2016, 10:01:50 AM »
you could put it on a pair of stand and see how much flex is there and that should give you a idea of how much strength you have lost and how much you gain back.

Bean

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Re: Naish Javelin- top rail redo, layering questions
« Reply #8 on: April 14, 2016, 11:15:43 AM »
In a perfect world, the rails would be shaped to your satisfaction, a layer of 6 or 4oz would then be laid down and the surface would be prepped for a core layer (wood veneer or divinycell) which would be vacuum bagged in place. This, in turn would be glassed with two layers of 6 or 4oz followed by a meticulous paint job...

You have a somewhat unique situation in that you don't have to bag the entire board, you could just bag each rail one at a time.  In place of vacuum bagging you could simply tape the core material down in this case since you have the top deck and bottom to tape against.

Having said that, Supuk's solution is very practical, the only thing I would add is to lay your 4" tape between the glass layers, centered on the rail.  It will add some stiffness and make the cosmetics easier.  If you blend in a brushed carbon look, the color match will not be as critical.   Take your time and have fun with this project.

If you haven't already done so, check out http://boardlady.com/repairmenu.htm, Eva has some great tips and tricks.
     

PonoBill

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Re: Naish Javelin- top rail redo, layering questions
« Reply #9 on: April 14, 2016, 12:26:16 PM »
Definitely the right way to do it Bean, though it would be a bitchy modification to get right. Even 1/8" core would be tricky to get a smooth transition. I'd expect that the board would stay pretty stiff even without core since the bottom curve of the rail is intact. With no continuous glass or carbon a plain upper rail won't contribute that much to stiffness unless it has a deep and well bonded overlap to the existing material, and even then who knows what it would really do. These kind of modifications are so problematic because they really change the nature of the structure. Hard to get them right. I've done this kind of stuff way too many times, it seems easier to just start from scratch. When I get back to Hood river one early project will be to get my finless race board in the water. It's going to take a lot of work to keep it from leaking. If I'd started with a blank, most of the workarounds I had to do wouldn't occur.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

supuk

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Re: Naish Javelin- top rail redo, layering questions
« Reply #10 on: April 14, 2016, 12:41:25 PM »
when you see inside some of the boards that are out there and how little glass and carbon is there you soon know how little you can get away with however durability is a major factor. Im doing repairs all day long, if you know what your doing and have all the stuff its easy but for a first timer keep it simple it doesn't have to be complicated and you will end up with something as solid as when it was new. The main thing to watch when doing repairs on eps is the temperature do not do any glassing when the temperature is increasing only when the board has been sat at a stable temperature for a good 1.5 hours will it stop out gassing and stop the chance of getting pin hole i can not emphasise this enough! secondly key up the surface your bonding to very well do not try glassing over any type of paint and make sure the surface is clean dry and dust free. I just had to repair a board that had been in a RTA the hole deck on the nose was delamed and creased 4 time. clean well overlaps is all it really needs.

Bean

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Re: Naish Javelin- top rail redo, layering questions
« Reply #11 on: April 14, 2016, 01:04:04 PM »
That Fanatic repair qualifies as a proper "restomod", very nicely done.  And yes, I've fallen prey to glassing on a rising thermometer at least a couple times.

PB, the CF tape would clearly be more cosmetic and could even result in a long-ass stress riser.   

PonoBill

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Re: Naish Javelin- top rail redo, layering questions
« Reply #12 on: April 14, 2016, 01:48:25 PM »
That Fanatic repair qualifies as a proper "restomod", very nicely done.  And yes, I've fallen prey to glassing on a rising thermometer at least a couple times.

PB, the CF tape would clearly be more cosmetic and could even result in a long-ass stress riser.

I agree. I'd do carbon only with a generous overlap to the existing structure, and I'd expect it to do funny things. My favorite repair these days for anything that's not structural is aluminum tape. At least I know I'm not adding weight or making hard spots.

Nice work Mr. Bean.
« Last Edit: April 14, 2016, 02:11:13 PM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

Bean

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Re: Naish Javelin- top rail redo, layering questions
« Reply #13 on: April 14, 2016, 02:40:15 PM »
I wish that was my work PB...that's actually UK's nice work you are looking at.


 


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