Softwood

[bhenry]

Hi, here are some pictures from Softwood ski building. My son and I have spent the last couple of years researching and building the various tooling required for this adventure. Thanks to all for the generous help along the way.

This is the adjustable height press. Our first mold iteration is similar to the PMGear Lhasa Pow. No carbon yet. We have built three pair so far using Super sap with heat top and bottom.


[/url]https://lh5.googleusercontent.com/-6RN- ... 20_001.jpg

https://lh4.googleusercontent.com/-2Ivo ... 20_006.jpg

First pair. Red cedar and western maple core. 2-11-2 with 22 oz triax top/ bottom. Really soft!

https://lh6.googleusercontent.com/-qVFh ... img][/img]https://lh3.googleusercontent.com/JgOwG ... -h207-p-no

https://lh6.googleusercontent.com/-WXBP ... img][/img]https://lh4.googleusercontent.com/-1w6d ... 28_002.jpg

Third pair. Bamboo 3- 12- 3 with about 15 cm flat in the binding area.
getting stiffer. Chili pepper Scarf donated by my wife, clear top sheet. I've put a couple days on these and I really like them.

The dimensions for the first three pair are 140- 112- 130.

[/url]https://lh3.googleusercontent.com/-SqJu ... 12_014.jpg

https://lh4.googleusercontent.com/-mwAB ... img][/img]https://lh4.googleusercontent.com/-eD0G ... 14_006.jpg

https://lh5.googleusercontent.com/-a57j ... img][/img]https://lh6.googleusercontent.com/-Giv0 ... 14_010.jpg

What we have learned-

This hobby is addicting...

The bases have been fairly flat. I took the third pair to my local REI and the shop guy was very helpful and interested. Hesitant to remove much material, but it was his first pair of homemade skis... It's a new store, and the equipment is brand new.

We routed for the edge teeth, but notice the ski top is not flat. About 1" from each edge the top starts to round off? The first two we pressed at 55 psi the third at 50. Same results. Ipe cat track may not be up to the job?

On the second pair the top sheet has taken some abuse in only four days. Top sheet getting peeled back. One issue, I think, was the sidewall bevel- 7 degrees. Now doing 15 and spending more time easing the top edge.
Using Duravision 5050. Would nylon be more durable?
For now the bamboo cores/ sidewalls are a slick way to go. I got enough material from a flooring contractor to build 12 pair for $120.

We use spray adhesive to hold the bases in place along with core spacer blocks super glued to the cassette. Seems to work real well.

Cutting off the flash has worked well using the 10 TPI bosch blade designed for hard wood, (don't recall the #). 2 pair on one blade and still going.

Epoxy amounts are around 850-950g per pair.

Pressing-

Load press, pressurize, turn on heat, takes +- 20 min. to get to 180. Hold for 20 minutes, turn off heat and wait until temp. drops to 150. depressurize and remove.

Well, that's all for now. Thanks, Bill

[bhenry]

Hi, here are some pictures of Softwood ski building. My son and I have spent the last couple of years researching and building the various tooling required for this adventure. Thanks to all for the generous help along the way.

This is the adjustable height press. Our first mold iteration is similar to the PMGear Lhasa Pow. No carbon yet. We have built three pair so far using Super sap with heat top and bottom.

[bhenry]

[/url]https://lh5.googleusercontent.com/-6RN- ... 20_001.jpg

https://lh4.googleusercontent.com/-2Ivo ... 20_006.jpg

[bhenry]

First pair. Red cedar and western maple core. 2-11-2 with 22 oz triax top/ bottom. Really soft!

[bhenry]

https://lh6.googleusercontent.com/-qVFh ... 25_006.jpg

[bhenry]

Second pair. Bamboo 2.5-11.5-2.5 with 22 0z triax top and bottom with clear top sheet. Still a bit soft, but my son really likes them

[bhenry]

https://lh4.googleusercontent.com/-prPg ... 10_009.jpg

https://lh6.googleusercontent.com/-WXBP ... 26_008.jpg

[bhenry]

Third pair. Bamboo 3- 12- 3 with about 15 cm flat in the binding area.
getting stiffer. Chili pepper Scarf donated by my wife, clear top sheet. I've put a couple days on these and I really like them.

The dimensions for the first three pair are 140- 112- 130.

https://lh3.googleusercontent.com/-SqJu ... 12_014.jpg

https://lh4.googleusercontent.com/-mwAB ... 14_001.jpg

https://lh5.googleusercontent.com/-a57j ... 14_003.jpg

https://lh4.googleusercontent.com/-eD0G ... 14_006.jpg

https://lh6.googleusercontent.com/-Giv0 ... 14_010.jpg

https://lh5.googleusercontent.com/-hs3p ... 14_004.jpg

[bhenry]

Well, that was ridiculous. My apologies, but I think I figured it out....Need to figure how to have the photo show on the page.

What we have learned-

This hobby is addicting...

The bases have been fairly flat. We routed for the edge teeth, but notice the ski top is not flat. About 1" from each edge the top starts to round off? The first two we pressed at 55 psi the third at 50. Same results. Ipe cat track may not be up to the job? On the second pair the top sheet has taken some abuse in only four days. One issue was the sidewall bevel- 7 degrees. Now doing 15. and spending more time easing the top edge.
Using Duravision 5050. Would nylon be more durable?
For now the bamboo cores/ sidewalls are a slick way to go. I got enough material from a flooring contractor to build 12 pair for $120.

We use spray adhesive to hold the bases in place along with core spacer blocks super glued to the cassette. Seems to work real well.

Cutting off the flash has worked well using the 10 TPI bosch blade designed for hard wood, (don't recall the #). 2 pair and still going.

Epoxy amounts are around 850-950g per pair.

Pressing-

Load press, pressurize, turn on heat, takes +- 20 min. to get to 180. Hold for 20 minutes, turn off heat and wait until temp. drops to 150. depressurize and remove.

Well, that's all for now. Thanks, Bill

[MontuckyMadman]

In my results 20min at temp for the supersap is not enough to fully cure the laminate at least in my press. We do at least 30 min at temp.

[bhenry]

Thanks for the tip MM.

I based part of my plan on your comments on letting it cool to 150 before pulling. Do you keep things under pressure until then as well?

[MontuckyMadman]

Yeah all the same. Actaully we are about 40min at temp. Takes care of the gooey edges of the cassette that way.

[bhenry]

MM,
I don't notice gooey edges, but I'm using sheet metal layers for the cassettes. They may reach a higher temp than say alum. I do need to better protect the bottom cassette. I've tried part all, but only one application.

The slight round over at the ski top edge is bugging me. Could it be the bladder is too close to the layup and is bending the ends of the Ipe cat track and possibly sealing off the edges preventing excess epoxy from squeezing out? The edge rabbit is about 3/10mm. Need a digital caliper.

https://lh4.googleusercontent.com/-tTjJ ... 20_002.jpg

[bhenry]

http://www.skibuilders.com/phpBB2/viewt ... highlight=

I found this thread that I hadn't read in a while and it might explain the problem with the edges being rounded. It still seems cat track deflection in the middle of the lay up is less likely.

It looks like I have several options;

Reduce pressure to lessen defection of the cat track.

Increase the gap between the upper and lower molds to decrease the contact area.

Eliminate the cat track and press like Shif does. My upper mold is fairly close in shape to the lower.

[vinman]

If you think you are trapping epoxy before you get enough squeeze out, try pressurizing for 5-10 min before you kick the heat on. This will allow you to squeeze out some epoxy and kind of let things equalize a bit before your epoxy really starts to kick.