What are the pros and cons of no top sheet, no cloth?

[hadley]

I mainly care about performance and weight in this back country ski I am working on. I think the lightest ski I can make will be one without any top sheet, just 6 oz for abrasion resistance. I am building a powder ski. I want to consider the pros and cons. The ones that occur to me are:
Pros:
1. It will be light
2. I can see into the ski to watch the progress of delamination etc.
3. A well built core is beautiful

Cons:
1. I am using vac. system and peal ply will leave a rough surface and not make the snow slide off quickly.
2. Without a top sheet the ski will wear more quickly.
3. I can see into the ski to watch the progress of delamination etc.
4. The bubbles usually hidden will be visible and make me a hypochondriac about wear.

I think I could spray the finished ski with spray varnish and smooth out the rough finish and give it some uv protection.

P.S. Plus then my Epoxy won't leak water;-)

[burny]

you could use an epoxy additive to colour your epoxy, so you cant see inside the ski and second, the uv-problem is solved. (but as far as i know, the uv-problem isnt really a problem because the amount of time the epoxy has to be exposed to the sun in order to turn yellow or eaven loose its sticking ability is much longer than the lifespan of any ski.)

to prevent snow sticking to your ski you can use a furniture polish paste or maybe some silcon spray.

my experience without a topsheet: it works nice, the skis are light and if you try to ski good and nicely, without hitting youre skis onto another, the skis will last a long time.


sorry, my english is really bad at the moment ...

[krp8128]

Tip: Don't use peel ply. For the final "release" use a smooth sheet of heavy (6 or 8 mil) plastic sheeting, followed by a smooth sheet of something fairly rigid. I used 1/8" Masonite, some people use extra base or topsheet material. Smooth as glass....

[MaRuMo]

I've made two skis, one with about 100 days on it sking it back country in Chamonix and the other one much less.

I don't have a top sheet, just glass and 3 layers of all weather outdoor vanish (not sure which brand is good int he US yet).

I never had delam problems myself. Just bevel the sides well, and route the sharp ridges a little. That works well too.

Idris's and I made light weight touring skis. His, with Dynafit bindings are 1.7kg per ski (185cm? I forgot). Mine is 160cm and more or less 1.6kg with his older Dynafit that's a hair heavier.

Compared our skis last season with a plastic topsheet and without. The looks are beautiful with just Vanish. Skis with the clear plastic topsheet started to look messy in places, kept delaminating at the tail despite repairs, and some other places where it takes hits often. My vanished top was very durable, easy to clean up and make it look like new again, and doesn't encourage delamination. At least not yet.

With the new skis, I have joint seams on the edge as we made our own wood cores out of palates I brought back from work to recycle. Mine, only in one spot probably where it didn't get enough resin cracked. I've fixed it and is doing just fine now. All the other seams have no issues.

There are some pictures here to get an idea to help your backcountry ski design. Best to look through the 'sets' as it's step by step with a write up

http://www.flickr.com/photos/26067326@N ... 792245888/
Ski Building 2007 and since then

Ski building Season 2007-08
http://www.flickr.com/photos/26067326@N ... 775321960/

Comparison 07/08
http://www.flickr.com/photos/26067326@N ... 880091120/