Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 27-03-2012, 15:22   #1
Registered User
 
akoutback1's Avatar

Join Date: Mar 2012
Posts: 4
Building With Kevlar

I have lots of kevlar and would like to build a 40'catamaran with some of it the kind i have is felt, 6 oz and 10.5 oz, this is the same as what the space shuttle is made from it still has the address on it to space center houston.so it should make a good cat. i have been looking online for info, on how to build one and can not find any thing on it. so if any one out there has any idea please let me know. thanks.
__________________

__________________
akoutback1 is offline   Reply With Quote
Old 27-03-2012, 15:39   #2
Registered User
 
tager's Avatar

Join Date: Apr 2009
Location: Vashon, WA
Boat: Haida 26', 18' Sea Kayak, 15' kayak, 6.5' skiff, shorts
Posts: 837
Re: building with kevlar

Something tells me that the design considerations of catamarans are not similar to those of a space shuttle.
__________________

__________________
tager is offline   Reply With Quote
Old 27-03-2012, 15:47   #3
Senior Cruiser
 
Blue Stocking's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: St. Georges, Bda
Boat: Rhodes Reliant 41ft
Posts: 4,117
Re: building with kevlar

Get Richard Branson on board (pun), and you got it made.
__________________
so many projects--so little time !!
Blue Stocking is offline   Reply With Quote
Old 27-03-2012, 15:54   #4
Ram
Registered User
 
Ram's Avatar

Cruisers Forum Supporter

Join Date: May 2005
Location: Cruising Greece
Boat: Cat in the med & Trawler in Florida
Posts: 2,298
Images: 27
Re: building with kevlar

if you can find someone with a cat who you can talk into putting the cat in a big pond of mud, this could be your mold then remove the cat, add the kevlar in the mud mold and epoxie and your half way done!- Im sure others will be able to help you on the rest of the boat!
__________________
Ram is offline   Reply With Quote
Old 27-03-2012, 15:55   #5
Registered User
 
akoutback1's Avatar

Join Date: Mar 2012
Posts: 4
Re: building with kevlar

ya, there is a difference in going up in space and the force of water. but i did make some calls and spoke to the maker of the kevlar. or the tec. and i was told it will do great also give the tensile strength, and told me the resin to use.
__________________
akoutback1 is offline   Reply With Quote
Old 27-03-2012, 15:59   #6
Head in a locker
 
Cavalier's Avatar

Cruisers Forum Supporter

Join Date: Dec 2010
Location: Houston, TX
Boat: Beneteau 461 47'
Posts: 879
Images: 1
Quote:
Originally Posted by tager
Something tells me that the design considerations of catamarans are not similar to those of a space shuttle.
On the other hand:
Both cost more than their 'mono' equivalents to build - and proportionally more to maintain;
You can have 're-entry' problems with both - especially if your customs clearance paperwork is not in order;
Neither of them have much difficulty flying over shoals;
Both have at least 2 engines, and;
I've never seen a cat above 490miles altitude either!
__________________
"By day the hot sun fermented us; and we were dizzied by the beating wind. At night we were stained by dew, and shamed into pettiness by the innumerable silences of stars."
Cavalier is online now   Reply With Quote
Old 27-03-2012, 16:04   #7
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,201
Images: 52
Re: building with kevlar

Quote:
Originally Posted by akoutback1 View Post
ya, there is a difference in going up in space and the force of water. but i did make some calls and spoke to the maker of the kevlar. or the tec. and i was told it will do great also give the tensile strength, and told me the resin to use.

Who was the maker of this particular Kevlar? Was it Reichhold Azusa that you spoke too? What resin did they recommend? I have done a lot of construction in carbon/kevlar, and I can tell you that kevlar and other aramids are almost never used in a laminate by themselves. Kevlar provides stellar resistance to abrasion and point loading, but very little stiffness. That is why it is almost universally used as an outer skin laminate only, and is also why it is almost always combined with carbon fiber. Carbon compliments it quite well, because where carbon is stiff and brittle kevlar is flexible and impossible to poke a hole in. Particularly for a cat, this would be a terrible construction material to use on it's own. Most of the boat needs to be a traditional laminate or better to make up for the lack of stiffness in the kevlar lam. Laminating in kevlar also requires special methods. It is almost always vacuum bagged in epoxy, with the kevlar buried between plies of S-glass or carbon. The reason is that you can't sand or grind kevlar-if you do it turns all fuzzy and becomes a real nightmare to work with. It's tricky stuff to use in a big build. Try talking to some builders who are currently using it instead of asking a manufacturer who just wants you to buy more product.
__________________
minaret is offline   Reply With Quote
Old 27-03-2012, 16:12   #8
Registered User
 
akoutback1's Avatar

Join Date: Mar 2012
Posts: 4
Re: building with kevlar

the guy said to get polymer risen.and he said it's costly
__________________
akoutback1 is offline   Reply With Quote
Old 27-03-2012, 16:48   #9
Registered User

Join Date: Aug 2011
Posts: 70
Re: building with kevlar

Quote:
Originally Posted by akoutback1 View Post
the guy said to get polymer risen.and he said it's costly
Polymer resin is so generic a term as to be meaningless. There are dozens of polyester polymer resins, dozens of polyurethane polymer resins, dozens of epoxy polymer resins.

A good place to start would be to get yourself a good book. Try the West Epoxy publications for details. Lots of (fairly general but informative) information on their web site as well. Epoxy by the Leading Epoxy Manufacturer | WEST SYSTEM Epoxy will get you started.
__________________

LH44 Anne is offline   Reply With Quote
Old 27-03-2012, 16:54   #10
Moderator Emeritus
 
David M's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: San Francisco Bay
Boat: research vessel
Posts: 10,152
Re: building with kevlar

This guy built a canoe out of Kevlar. Yes I understand this is very different, but there may be some similarities and ideas in this link for you....

How to Build a Kevlar Canoe

I think if you find an old catamaran hull and use it as a mold you already have a good start, as opposed to building your own mold.

Keep in mind a 40 foot boat is going to take a few thousand man-hours.

Now I want to build my own Kevlar canoe in my workshop.
__________________
David

Life begins where land ends.
David M is offline   Reply With Quote
Old 27-03-2012, 17:38   #11
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,201
Images: 52
Re: building with kevlar

Quote:
Originally Posted by David M View Post
This guy built a canoe out of Kevlar. Yes I understand this is very different, but there may be some similarities and ideas in this link for you....

How to Build a Kevlar Canoe

I think if you find an old catamaran hull and use it as a mold you already have a good start, as opposed to building your own mold.

Keep in mind a 40 foot boat is going to take a few thousand man-hours.

Now I want to build my own Kevlar canoe in my workshop.
If you actually read the instructions in the link, you will note that the canoe is mostly S-glass with a layer of kevlar for chafe protection when beaching the canoe. That's two plies of S-glass with a single ply of kevlar in the laminate schedule, for exactly the reasons I mentioned earlier. I got my start in the early days of carbon/kevlar, vacuum bagging and pre-pregs building production sea and white water kayaks, so I've cranked out many a kevlar 'yak. Noone uses kevlar by itself because you would end up with a boat like a noodle. Someday when you are in your local REI compare the panel stiffness of a straight S-glass kayak to a carbon/kevlar kayak. You will immediately notice that despite the attempt to compensate by using carbon, the kevlar boat will "oil-can" much easier than the S-glass boat will, even though they have the same number of plies in the laminate schedule and the same hull thickness.
__________________
minaret is offline   Reply With Quote
Old 27-03-2012, 18:23   #12
Registered User
 
cat man do's Avatar

Join Date: Aug 2006
Location: Brisbane Australia [until the boats launched]
Boat: 50ft powercat, light,long and low powered
Posts: 4,409
Images: 36
Re: building with kevlar

Quote:
Originally Posted by minaret View Post
I have done a lot of construction in carbon/kevlar, and I can tell you that kevlar and other aramids are almost never used in a laminate by themselves. Kevlar provides stellar resistance to abrasion and point loading, but very little stiffness. That is why it is almost universally used as an outer skin laminate only, and is also why it is almost always combined with carbon fiber..
Geoff Cruse is a builder here in Brisbane who has built many cruising cats like these Crowther Windspeeds and Supershockwave's




Mostly 20mm foam, 200gsm kevlar in and out and usually just a layer of 400gsm biax on the outer for abrasion and impact resistance.
All done with epoxy, but nothing fancy.

The only carbon used on these boats was in the mast of the first one. (supershockwave)

as stated here http://www.tbns.net/xl2/72_04_81.htm the shockwaves in their original form below (XL2, Wahoo, D-Flawless) used 5oz kevlar

__________________
"Money can't buy you happiness but it can buy you a yacht large enough to pull up right alongside it"...............David Lee Roth
Long Distance Motorboat Cruising It Is Possible on a Small Budget
cat man do is offline   Reply With Quote
Old 27-03-2012, 18:59   #13
Registered User

Join Date: Nov 2011
Location: Montegut LA.
Boat: Now we need to get her to Louisiana !! she's ours
Posts: 3,421
Re: Building With Kevlar

I know nothing about Kevlar other then I think it's used in Bullet Proof Vests, but that Cat shown in the the last pic Looks Just Plain FAST !! must be a real thrill to sail aboard !! So much is going on out there these days with new Ideas and materials it really great even for us old guys LOL I look forward to seeing vessels like this on line and I hope in the near future in person !!
__________________
Bob and Connie
bobconnie is offline   Reply With Quote
Old 27-03-2012, 19:21   #14
Registered User
 
cat man do's Avatar

Join Date: Aug 2006
Location: Brisbane Australia [until the boats launched]
Boat: 50ft powercat, light,long and low powered
Posts: 4,409
Images: 36
Re: Building With Kevlar

Quote:
Originally Posted by bobconnie View Post
but that Cat shown in the the last pic Looks Just Plain FAST !! must be a real thrill to sail aboard !!
She's pretty quick thats for sure

Quote:
In 1993, a race record of 20 hours 50 minutes was set by Paul Nudd on his catamaran XL2 for the 300nm Brisbane to Gladstone yacht race. Unfortunately for Paul, the record is not recognised by the World Speed Sailing Council as he went to the aid of another yacht and his adjusted time would not be officially recorded by them.
Race History




Quote:
So much is going on out there these days with new Ideas and materials
XL2 is at least 25 years old
__________________
"Money can't buy you happiness but it can buy you a yacht large enough to pull up right alongside it"...............David Lee Roth
Long Distance Motorboat Cruising It Is Possible on a Small Budget
cat man do is offline   Reply With Quote
Old 27-03-2012, 19:23   #15
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,201
Images: 52
Re: building with kevlar

Quote:
Originally Posted by cat man do View Post
Geoff Cruse is a builder here in Brisbane who has built many cruising cats like these Crowther Windspeeds and Supershockwave's




Mostly 20mm foam, 200gsm kevlar in and out and usually just a layer of 400gsm biax on the outer for abrasion and impact resistance.
All done with epoxy, but nothing fancy.

The only carbon used on these boats was in the mast of the first one. (supershockwave)

as stated here This appeared in Volume 2 Number 7 of the shockwaves in their original form below (XL2, Wahoo, D-Flawless) used 5oz kevlar

Note that the laminate schedule for the teeny canoe linked to above is three times thicker than you claim they are skinning 3/4" inch thick foam hulls with! More actually as it calls for 3 plies of 6 oz. instead of one ply of 5 oz. I'd never go to sea to cruise in a boat with fiberglass less than 1/16" thick, that's madness! Fine for racing but what happens when you beach the boat or run aground or hit something, which as we all know is fairly inevitable for most serious cruisers? Laminate schedules that light in a structure that undergoes the stresses a catamaran does just cannot possibly have the same longevity as a serious cruising design. I don't think you can compare these designs to a normal production cruising cat in any way, as I've told you before. You can find all sorts of extremes to make your point but it doesnt really help the discussion any. Show me a production cruising cat with ONLY kevlar in the laminate, I challenge you! Even the examples you already mentioned have as much glass in that single biax than in the kevlar skins, making it a 50/50 mix as I already suggested, and I'm sure they were the most extreme examples you could find!
__________________

__________________
minaret is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Building With Kevlar akoutback1 Monohull Sailboats 16 28-08-2012 08:37
Hello ! From a Young Sailor with No Experience abonville Meets & Greets 7 13-04-2012 23:09
For Sale: Pair of Yanmar 3GM30 FC with saildrive (year 2000) yachtiritis Classifieds Archive 1 01-04-2012 06:02
Crew Available: Panama Canal Transit - Anytime in April with Advance Notice wildlawnc Crew Archives 4 26-03-2012 18:00
Smart Pilot X-5 with NMEA 2000 gpeacock Marine Electronics 4 26-03-2012 11:22



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 02:56.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.