Ski Builders Forum

B Kam,

How are you laminating the Aluminum? Are you pre-etching or abrading the material right before laminating. Or maybe something else? How much glass and what weight did you use. On some of the Snowboards they use a light weight carbon uni and just the Titanal, essentially replacing the glass with the metal.

Carvejunky

Carvejunky: i abraded the surfaces using low-grit sandpaper, then cleaned with a solvent and immediately laid-up (note: AL oxidizes rather quickly.). in general it's tricky to get a good bond -- it still eludes me, but i'm getting better at it...

I did many practice runs of Al gluing. Steel wool does not properly abraid if you want to have good sticsion. I tested with a 180 grit sand paper that with light abrasion and got great adhesion. I'm going to use more elbow grease next time.

Aluminum Bonding can be greatly enhanced by Phosphoric Acid Anodizing. Thats what Boeing uses to glue together planes.

" PAA, phosphoric acid anodize is also Boeing's BAC5555 process. It is used for structural adhesive bonding, per ASTM-D3933, and substantially improves performance in high-humidity environments "

You could look around for someone who does Aircraft anodizing and see if they do PAA. I found a place close to me that does it but I don't have pricing yet. I am going to try it this summer on a couple of boards I am going to do.

B Kam: What Fabric weight did you use in your pallet ski's?

Carvejunky

big kam,

really sweet looking skis as usual. cool to see that you are pushing the
the standards of homebuilts with alum. and dampening layers to improve
performance and edge hold, chatter, etc... can't wait for the full story and test of these planks. did you notice camber changes with your mold with heat verses no heat???? very interested in your observations.

jason

Carvejunky: i don't know the weight, but it's rather thin. it's nothing fancy though -- bought it at Walmart for $1.99/yard.

Jason: i'm using a zero camber mold, and i get about 5-8mm of camber because of the heat -- has to do with difference in thermal expansion of the materials when heat is applied. Kelvin and i have experienced this from the beginning, so we compensate by using a zero-camber mold. one thing i should try is may wait until the skis completely cool under pressure before removing them -- but i'm impatient...

i'm laying up another pair this Friday, and three more cores are waiting their turn. i'm using left-over wood found in the rafters of my garage. it must be 10-years old, and was left here by the previous owners of my house. i'm putting it to good use.

It kinda makes sense using old wood that has been lying around for ages. It is completely dried out and stable.

Thinking that I will try to find some left over or old wood when it´s time to build my first pair of skis. Extending the length of the pieces should be no biggie. Either do like you did, or join the individual pieces. (Sawtooth pattern on the endgrain, don´t know what its called in english though) This is common practice in the wood industry, especially when making glulam beams or solid wood elements. Low quality wood is frequently used in these processes, but this is no problem as variations in quality are evened out by having many stringers.