*


All times are UTC + 1 hour



Post new topic Reply to topic
 [ 25 posts ]  Go to page 1, 2, 3  Next
Author Message
 Post subject: building a SUP how do you strengthen it for kiteboarding?
PostPosted: Thu Jun 06, 2013 8:44 pm 
Online
Very Frequent Poster
User avatar

Joined: Fri Jul 16, 2010 6:27 am
Posts: 2394
Location: Ford Lake, Michigan
Can I drill holes thru the blank and let epoxy go thru to fix the top and bottom deck together? maybe double layers of glass, or corecork? kiting is a lot harder on a SUP than paddling or surfing, I know I will slam it.


{ SHARE_ON_FACEBOOK } { SHARE_ON_TWITTER } { SHARE_ON_ORKUT } { SHARE_ON_DIGG } { SHARE_ON_MYSPACE } { SHARE_ON_DELICIOUS }
Top
Profile
 Post subject: Re: building a SUP how do you strengthen it for kiteboarding
PostPosted: Thu Jun 06, 2013 9:37 pm 
Offline
Very Frequent Poster

Joined: Wed Nov 20, 2002 1:00 am
Posts: 910
Location: rhode island
you may be right.
but unless you figure a way to jump with it, i doubt the damage will be that severe.

SUPS are thick, with padding?
and not much bending.

assuming you do damage it, i would wait to find out what the specifics are.
then make repairs

....something like a section of sheet foam to beef up the skin.
the eva pad can be tailored to dress up the repair.

just a thought


Top
Profile
 Post subject: Re: building a SUP how do you strengthen it for kiteboarding
PostPosted: Thu Jun 06, 2013 10:15 pm 
Offline
Very Frequent Poster

Joined: Sat Aug 29, 2009 11:25 pm
Posts: 2507
Location: The Naki
Hmmm..

Ok my ideas.

For a start use epoxy resin and not polyester.
you could simply add extra layers. I'm assuming it has a wood stringer like a surfboard. Adding an extra couple of these would help.

Carbon at the foot placements to prevent denting.

Check out bro kite kiteboard construction videos. it would be pretty easy to band saw your blank into 1/4's and laminate several "I Beams" into the core.


Top
Profile
 Post subject: Re: building a SUP how do you strengthen it for kiteboarding
PostPosted: Thu Jun 06, 2013 11:16 pm 
Offline
Very Frequent Poster

Joined: Thu Feb 20, 2003 7:14 pm
Posts: 583
If you want strong but still reasonably lightweight, then you need sandwich construction.

Corecork might work great but I have no experience with it. Balsa wood, corecell, and divinycell are also great choices for sandwich cores.

With a sandwich build you can use the lightest possible eps foam for the core. there is no point having a stringer.

Trent


Top
Profile
 Post subject: Re: building a SUP how do you strengthen it for kiteboarding
PostPosted: Fri Jun 07, 2013 4:46 am 
Online
Very Frequent Poster
User avatar

Joined: Fri Jul 16, 2010 6:27 am
Posts: 2394
Location: Ford Lake, Michigan
tks for the tip not, I'll try making it a sandwhich, didn't realize it added so much strength that's just what I was looking for.


Top
Profile
 Post subject: Re: building a SUP how do you strengthen it for kiteboarding
PostPosted: Sat Jun 08, 2013 2:57 pm 
Offline
Medium Poster

Joined: Fri Apr 06, 2012 2:01 pm
Posts: 135
sandwich and reverse drop stitch !

what ?

chech out inflatable sups, then think reverse :

you want the deck and bottom to stay at equal distance, but, pressure is not comming from inside but outside.

so drill holes between top and bottom, but, for more then one third of inch, only resin inside wont work.

so, take fibers of glass, or better, carbon fibers and put them thought the holes. glue them on top and bottom, only, you can do that one hole at the time or easyer stich them throug mutiple holes in a continus pass, just stick them to botto and top, dont put resin in the holes.

then, once you do your vacuum laminate, IF you do it bottom first, the resin is going to flow throug the holes and you'l end up heaving carbon fiber mini rods betwin top and bottom.

this way, you can use lighter foam and have an enormus strenght between top and bottom sheets.


Top
Profile
 Post subject: Re: building a SUP how do you strengthen it for kiteboarding
PostPosted: Sat Jun 08, 2013 3:58 pm 
Offline
Medium Poster

Joined: Sat Nov 24, 2012 3:33 pm
Posts: 115
edt wrote:
tks for the tip not, I'll try making it a sandwhich, didn't realize it added so much strength that's just what I was looking for.

That is incredibly bad advice. A sandwich structure does not add any strength, it adds bending stiffness!

In fact what you are looking for is impact resistance, toughness and strength. The easiest way to accomplish this is to add more layers of carbon or glass fiber (assuming equal strength layups where you have to add ~1.5x the weight with glass). Fracture toughness and fracture energy is roughly the same for both well made CFRP and GFRP.

Furthermore you could add EVA pads where you stand as this soft medium will help disperse some of the impact energy.

Since the a SUP is used in very low winds I would just add four layers of 150ish gsm glass fiber and epoxy to the deck stand area and then let that taper down toward the front and back of the board where you do not stand.

You could also buy pre-fabricated GFRP plates if the stand area on the SUP is completely flat.


Top
Profile
 Post subject: Re: building a SUP how do you strengthen it for kiteboarding
PostPosted: Sat Jun 08, 2013 4:06 pm 
Online
Very Frequent Poster
User avatar

Joined: Fri Jul 16, 2010 6:27 am
Posts: 2394
Location: Ford Lake, Michigan
FrederikS wrote:
Since the a SUP is used in very low winds


I am using my SUP as a boat to move my kite gear across the lake, should be reaching speeds of 20+ mph in big waves, anticipate quite a few heavy crashes in these conditions. The only time I will paddle is if the wind dies or line snaps and I have to get back to the launch.


Top
Profile
 Post subject: Re: building a SUP how do you strengthen it for kiteboarding
PostPosted: Sat Jun 08, 2013 4:08 pm 
Offline
Medium Poster

Joined: Sat Nov 24, 2012 3:33 pm
Posts: 115
edt wrote:
FrederikS wrote:
Since the a SUP is used in very low winds


I am using my SUP as a boat to move my kite gear across the lake, should be reaching speeds of 20+ mph in big waves, anticipate quite a few heavy crashes in these conditions. The only time I will paddle is if the wind dies or line snaps and I have to get back to the launch.


Then it is probably best to give it a thin layer of glass fiber all the way around and then double up where you stand.


Top
Profile
 Post subject: Re: building a SUP how do you strengthen it for kiteboarding
PostPosted: Sat Jun 08, 2013 4:30 pm 
Offline
Very Frequent Poster

Joined: Thu Jun 05, 2003 3:37 am
Posts: 2374
Stitch through idea or many stringers might be too heavy and stiff for sup I think. I would just do a sandwich deck of 2-3mm high density foam (corecell or d-cell etc) or thin okume plywood, veneer etc.

Frederiks idea is correct in a way but only partly.
Its right mainly IF he means having a sandwich deck AND sandwich bottom. But many board builders have known for many years a sandwich deck helps against impact and heel dents.
By making the laminate thicker it is stiffer and resists impact. The recipe is different to maximize stiffness and light weight.
For example:
stiff and light = eps core, 2 oz glass, core cell, then 4-6oz glass on top. This sandwich can wrap the rails and deck
Impact resistant = eps core, 4-6 oz glass, THIN corecell or ply or veneer ( or even just a thick hot coat), then 6-8 oz glass on top.
Or you can just add a few glass layers on deck!


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic
 [ 25 posts ]  Go to page 1, 2, 3  Next

All times are UTC + 1 hour


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group