Best material for abrasion resistance

See our FAQ and tutorials before posting.
User avatar
gstanfield
* Bateau Builder *
* Bateau Builder *
Posts: 4500
Joined: Sun Jan 10, 2010 5:09 pm
Location: Rolling Hills, WY

Best material for abrasion resistance

Post by gstanfield » Fri Feb 19, 2010 10:38 am

We discussed this a little in my build thread, but I thought I would post a new thread and get some more opinions and maybe some definative answers to my question. I'm wanting to add a layer of glass to the bottom of my FL14 due to our river being shallow in places and a pure gravel bottom. I know that Biax is stronger from a torsional and sheer strength perspective, but is it better for abrasion than woven? Just so you know, this boat will be loaned out a lot to family, friends, etc. and I know that most people don't know how to read the river and they will end up sliding across gravel bars time after time after time after time....

SO, what's best for abrasion?

Thanks,
George



User avatar
jacquesmm
Site Admin
Site Admin
Posts: 27238
Joined: Wed Aug 14, 2002 1:00 am
Location: Florida USA
Contact:

Re: Best material for abrasion resistance

Post by jacquesmm » Fri Feb 19, 2010 10:46 am

Kevlar is the best but difficult to apply.
The best compromise is an extra layer of glass like you propose plus an epoxy-graphite coat.
That coat is simply epoxy resin mixed with graphite (carbon powder).
There is no significant difference in abrasion resistance between woven and stitched fabrics.
Jacques Mertens - Designer
http://bateau.com

User avatar
tech_support
Very Active Poster
Very Active Poster
Posts: 12319
Joined: Wed Dec 31, 1969 7:00 pm
Location: Vero Beach, FL
Contact:

Re: Best material for abrasion resistance

Post by tech_support » Fri Feb 19, 2010 10:51 am

The difference would not be noticeable or even worth much consideration. Thickness of the glass is going to determine how abrasion resistant it will be (Biax of same weight will normally be a little thicker) . If you want to step up the abrasion resistance, go thicker or use another material like kevlar or a layer of dynel over the glass.

User avatar
gk108
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 3356
Joined: Thu Jul 28, 2005 6:53 pm
Location: The Peach State

Re: Best material for abrasion resistance

Post by gk108 » Fri Feb 19, 2010 11:23 am

I used 6 oz woven glass and graphite on my D15 and it has held up well. For a slow boat like the FL14, I think it would sufficient, unless you are doing some extreme river boating. I often beach the boat or run it up on a log on a river bank and the surface of it just sort of polishes down. It works pretty good for sand, gravel and stuff like that where the forces are spread out over several square inches. I bumped a limestone outcropping once and gouged it a little, but didn't go through the glass. The hardest part about repairing that was figuring out how to make a tiny batch of graphite/epoxy.
CC, D15, V10

User avatar
gstanfield
* Bateau Builder *
* Bateau Builder *
Posts: 4500
Joined: Sun Jan 10, 2010 5:09 pm
Location: Rolling Hills, WY

Re: Best material for abrasion resistance

Post by gstanfield » Fri Feb 19, 2010 11:42 am

Thanks for the advice, I'll just go with a layer of biax and some graphite to make things nice and tough.

George

Chief Brody
Very Active Poster
Very Active Poster
Posts: 542
Joined: Wed Jun 24, 2009 3:46 pm

Re: Best material for abrasion resistance

Post by Chief Brody » Sun Feb 21, 2010 9:53 pm

Jacques/Joel,

can you please explain why or how Kevlar is more dificult to work with than glass? We use it at work for cold laminations and it seems OK when compaerd to ther types of material...but that is a completely different process than boat building with resin....is it a wet out issue?

TomW
Very Active Poster
Very Active Poster
Posts: 10123
Joined: Fri Feb 23, 2007 10:41 am
Location: Smoky Mts of NC

Re: Best material for abrasion resistance

Post by TomW » Mon Feb 22, 2010 12:38 am

Chief, Kevlar tends to want to float and is hard to wet out in a resin lamination like ours. It can be done it is just much more difficult and requires a lot of patience and care to make sure it is wetted out properly taking more epoxy than is needed. If a guy could vacumn bag it, it would not be so bad.

We have had this discussion come up before. You could probably find more info down in the fiberglass, resins and paint section. :D

Tom
Good fishing and red skys at night sailors delight
C17ccx, Mirror Dinghy

User avatar
tech_support
Very Active Poster
Very Active Poster
Posts: 12319
Joined: Wed Dec 31, 1969 7:00 pm
Location: Vero Beach, FL
Contact:

Re: Best material for abrasion resistance

Post by tech_support » Mon Feb 22, 2010 9:30 am

yes, it floats more than glass. It is not as easy to determine when you have enough epoxy (does not go clear or change color much). The fact that it cannot be sanded is what makes it most unfriendly. You can apply a layer of glass over the kevlar, so you have something to sand. You can certainly use it and for some builders with extreme conditions it may be the best choice, its just comes at a cost (in dollars and time) that makes it not a good choice for 90% of these boat.

I have a very large roll of 9 oz kevlar just waiting for a project. I thought I would use it for my FS17, but I didnt because I didnt want the hassle, and Im glad because even with all the beaching I do, i have never come close to having an issue with abrasion.

Maybe if we build a big catamaran here, then I will get to use that kevlar :) :wink:

Chief Brody
Very Active Poster
Very Active Poster
Posts: 542
Joined: Wed Jun 24, 2009 3:46 pm

Re: Best material for abrasion resistance

Post by Chief Brody » Mon Feb 22, 2010 10:06 am

Gotcha.....the reason for asking is that I've seen some boat builders use it in the lamination schedules when building a cored boat (according to them) for impact protection.....which Kevlar does very well.....and they use different methods of application....one being infusion with VE, another being "wet preg" with epoxy and then bagged and post cured....and a third production builder using it for a single skin-hand laid application, and maybe using just PE resin.....3 different methods, 3 different resins....just wondering what they each had to do different to handle the fabric.
Tom/Joel, thanks for the expalnation.

User avatar
tech_support
Very Active Poster
Very Active Poster
Posts: 12319
Joined: Wed Dec 31, 1969 7:00 pm
Location: Vero Beach, FL
Contact:

Re: Best material for abrasion resistance

Post by tech_support » Mon Feb 22, 2010 11:35 am

with vacuum bagging or infusion there is almost zero sanding, and if its made in a female mold then its very easy to use. Also, with a foam core hull all your impact loads are taken by the skin, where in our ply core composite we have good impact from the plywood. So a foam core boat gets a lot of benefit from the kevlar.

You could use a kevlar with our plywood composite deisgns, but it would unnecessary for strength and a very expensive over kill for impact.

Post Reply

Who is online

Users browsing this forum: No registered users and 25 guests