Ski Builders Forum

Yep per pair. Wet out base and edges, glass, both sides core, usually a 50-65mm carbon uni full length, and wet out under side of topsheet.

Im less than 1000g for 187 150-120-134. pair.
same wet out as falls.

In my experience Carbon eats much more then Glass. Not sure why, perhaps it the way it is 'woven'. I also noticed that same glass weight can eat different quantity of Resin depending on the way it is 'woven' . If you look at glass from 2 different suppliers, one can have much more air pockets then the other.

M, It helps to distinguish between wood core and bamboo cores. Wood cores absorb an amount of resin, bamboo won't.

FG and Carbon have slightly different resin requirements, but it's not worth worrying about. Neither fabrics absorb the resin.

A fabric will wet out more efficiently by raising the temperature of the fabric/resin or both - but only raise the temp of the resin slightly, as the fumes can be nasty. Putting your fabric in the airing cupboard overnight is a good thing to do in advance of pressing. As this eliminates any moisture.

How much you should use depends on the fibre fraction you want. 60% resin to 40% fibre is a good place to start. This calculator will tell you how much resin to use by weight.

http://www.netcomposites.com/calculator ... -fractions

Factor in waste, resin absorbed by the core (a good thing) and individual coating of parts (depending on your fancy).

How much resin remains is the issue you need to address and will vary according to the amount of pressure. Heat is a factor, but don't worry about it. Its something that can be refined at a later date.

Do you wet out in the mold MM or on a separate table.
I think viscosity of the resin (esp when you don't have control of the room temp) plays a big part. Also the bundle size in the triax. I have trouble even at 35C when the resin is really liquid getting the 22oz (186cm by 165mm) to look as wet as I want it to all over.
I think I'm using too much on the edge/base and prob too much on the core.
Also my glass is far wider than it needs to be for the skis I'm making so I could trim it to shape and use less.

[quote="Richuk"]M, It helps to distinguish between wood core and bamboo cores. Wood cores absorb an amount of resin, bamboo won't.

Ive been looking for some bamboo to try but this is interesting; if Bamboo wont take epoxy, is it worth using?

I've not explained what I meant very well.

Bamboo - high strength, low weight. It's has good mechanical properties. I've not used it, but I'm sure Falls can speak to its pro's and con's.

Bonding bamboo is like bonding plastic - you are just bringing two pieces of plastic together and the epoxy required depends on the thickness of the bondline.

If follows that the amount of epoxy required to layup is less, when comparing a comparable lay-up using a wood core.

Wood has pores and vessels and things like that. Depending on the wood, epoxy and cure cycle, these areas within the wood core becomes saturated - to a greater or lesser degree. Changing the mechanical properties of the wood, whereas the mechanical properties of the bamboo are unchanged.

If you want to see the distinction, I have a photograph taken under a microscope.

FWIW, my process sounds very similar to yours Falls, including the width of 22oz triax I'm wetting out, so no surprise that our epoxy use is about the same. One difference, it sounds like, is that I'm wetting out the triax outside of the mold and am able to wet out one side, flip the triax over and finish wetting it out from the other side. So, even though I'm doing this in a relatively cool basement environment (55 F or 13 C), I don't have any trouble fully wetting it out. Once in the vacuum bag, I build a box around the mold using insulation panels and, with a couple space heaters, get the temp up to 140-150 F.

I wet out on a separate table, but don't usually flip the glass over. I have done that on occasion and maybe I need to do it more often/all the time.

The bamboo adheres fine with epoxy, but Rich is right that the glue doesn't seem to penetrate the "wood". Probably accounts for a fair bit of squeeze out under pressure as the epoxy I place on the core has nowhere to go but outwards leaving only a thin bond line.

A bit of cherry picking it terms of applicability, but interesting:

http://books.google.co.uk/books?id=6jQp ... on&f=false

and this:

http://arxiv.org/ftp/arxiv/papers/1007/1007.0762.pdf

The points they make about resin viscosity and porosity of the core material highlights the importance of preserving a good bondline as part of the final thickness of the laminate. It sort of depends on whether you think VDS is important or not so much, as the bondline can be thought of as fulfilling a similar function.

https://vimeo.com/120267722
Here is the time lapse of my latest build. You can see the glass wet out pretty well (prob 30C temperature) and I did flip the end to work on some troublesome spots.

Your women just had a huge sandwich for lunch.....or she's packing Falls jr.

Congrats dude,

Derek

yeah our daughter arrived 12 days ago!
My wife normally helps with layup. The last few pairs she has just helped load the press. I felt bad even doing that. The baby doesn't smell like epoxy

Congratulations Tim and Mrs.

Had to laugh, 1:43 watching paint dry.

sam

Thanks
Watching for fires more like it. I have always been scared of things going up in smoke after ON3P set fire to their press in their first year. Not sure what I would do though, prob throw my beer on it.