Materials - is that good?

For discussions related to the type of materials to build skis/snowboards and where to get them.

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Dimitar
Posts: 70
Joined: Thu Jan 03, 2013 7:02 am
Location: Bulgaria

Materials - is that good?

Post by Dimitar »

As Head Monkey told me the most difficult part of snb building is finding materials for reasonable price. Last 2 months I spent looking for good suppliers here in Bulgaria. So I found almost all of the necessary materials. I`ll be glad to know your opinion about the prices and specifications written below:

Epoxy and hardener
www.5m.cz/userfiles/file/Lepidla%20EN/T ... 3%20en.pdf

Viscosity: 0.8-1.3 [Pa.s]
Shear strength: 20-25 [Pa]
Color: Natural
Curing temperature: 70 Celsius degrees (158 F)
Price: 22 euro/kg

Fibreglass
Triaxial 0/+45/-45 (384/220/220 gr./sq.m.)
Total densisty: 824 gr./sq.m.
Price: 6.30 euro/sq.m.

Kevlar
Density: 170 [g/sq.m.]
Price: 30 euro/sq.m.

Carbon fibre
Density: 240 [g/sq.m.]
Price: 36 euro/sq.m.

Are these materials suitable for snb building?

Thanks
Dimitar
Last edited by Dimitar on Mon Jun 03, 2013 1:00 am, edited 1 time in total.
maximegb5
Posts: 49
Joined: Sun Oct 04, 2009 12:30 pm

Post by maximegb5 »

I don't know about the epoxy, but it seems like a decent deal. And I think it seems suitable for ski building. But I have never tried that epoxy.

As for the kevlar and carbon fiber, it really depends on the orientation of the fibers. You want to have a biaxial sheet at +/-45 for the carbon fiber, and the density will depend on the strength of this particular carbon. I am personnaly using 190gsm biaxial carbon fiber, and it is quite stiff. 240gsm might be a bit too much, but it also depends on other factors, and I don't know what type of kevlar has been used and to what utility. It seems more like a PITA than anything else, as it does not seems to be really useful in a ski.

Good luck!
Dimitar
Posts: 70
Joined: Thu Jan 03, 2013 7:02 am
Location: Bulgaria

Post by Dimitar »

maximegb5 wrote:
I don't know what type of kevlar has been used and to what utility. It seems more like a PITA than anything else, as it does not seems to be really useful in a ski.

Good luck!

Thanks maximegb5, actually I `ll build snowboards so I`d like to use kevlar for inserts reinforcement.

Dimitar
Richuk
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Joined: Sun Jan 31, 2010 9:53 am
Location: The Duchy of Grand Fenwick

Post by Richuk »

The data sheet defines this as an adhesive and it sounds expensive. Did they say why they recommend this epoxy for your application?

This thread will help you survey what others are using: viewtopic.php?t=2947&postdays=0&postorder=asc&start=0.

If you have any boat/yacht building taking place in Bulgaria, they maybe a source of good local knowledge. It might be worth following the approach taken by SD and use a good polyester resin, it will get you started at least.
Dimitar
Posts: 70
Joined: Thu Jan 03, 2013 7:02 am
Location: Bulgaria

Post by Dimitar »

Richuk wrote:The data sheet defines this as an adhesive and it sounds expensive. Did they say why they recommend this epoxy for your application?
I sent them a request for epoxy resin suitable for manual layup of snowboards and they sent me an offer for epoxy adhesive (I`m wondering if there is clear difference between resin and adhesive).

And here www.5m.cz/en/epoxy-adhesives-1/ is written that these adhesives are mostly used for production of sport equipment (ski, icehockey sticks or snowboards).

The people I`m in contact are just sellers (they don`t even know what is viscosity... wtf?). :D:D:D

However, they will send me a sample of 2 kg., so I could make some tests before to buy it. But I want to be sure if I`m ordering the right sample...
Richuk
Posts: 1146
Joined: Sun Jan 31, 2010 9:53 am
Location: The Duchy of Grand Fenwick

Post by Richuk »

Provided the recommendation is coming from 5m.cz and not the re-seller, then I wouldn't be too worried at this stage.

It is worth compiling data on the mechancial performance of the epoxies listed in the link (e.g. flexural strength and elogation). Then go back to your supplier and make the request for this missing data.

If you have a local composite forum, they should offer a guide on price.

Resin/Adhesive ... I'm not sure I have an answer. Perhaps it works to think about it in terms of a resin being closer to the original chemical formulation and an adhesive being a derogation of the formulation, designed for a specific purpose. I would imagine the line between the two would vary depending on the type of supplier you are dealing with.
knightsofnii
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Location: NJ USA
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Post by knightsofnii »

what's in a name?

I think "adhesive" is a very vague term and i dont think there's really any rhyme or reason for why someone uses it as opposed to resin.

When I think of the term "resin" I think of simply the "part A" of the resin/hardner mix.

Doesnt adhesive just mean something used to bond things together? The way i see it, all epoxies are adhesives... unless they're paints or coatings.
Doug
mikic1
Posts: 183
Joined: Tue Nov 15, 2011 11:51 am
Location: sweden

Post by mikic1 »

U can get Entropy resin, used by many guys here, I my self have been very happy with it, they have a number of products depending on your approach.

Talk to Jaime, he is distributing in Europe.

http://www.entropyresins.eu/

I am sure you will get a price much better then 20 euro/kg for bit larger quantity.
Dimitar
Posts: 70
Joined: Thu Jan 03, 2013 7:02 am
Location: Bulgaria

Post by Dimitar »

mikic1 wrote:U can get Entropy resin, used by many guys here, I my self have been very happy with it, they have a number of products depending on your approach.

Talk to Jaime, he is distributing in Europe.

http://www.entropyresins.eu/

I am sure you will get a price much better then 20 euro/kg for bit larger quantity.
Thanks, @Mikic1. Which resin do you recommend for pneumatic pressing + heating?
mikic1
Posts: 183
Joined: Tue Nov 15, 2011 11:51 am
Location: sweden

Post by mikic1 »

For that I use CPM from Entropi.
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