Ski Builders Forum

I ended up mothballing the whole works a couple years years ago before ever getting a single board made. Now that we're debt free and the kids have stopped being born, it's time to get after it. Got the press out, wiped off the cob webs and pumped her up. 60psi, no leaks and the framework seems to handle the stress easily. Gotta love homebrew engineering. I almost can't believe it still doesn't leak. Materials ought be on order in the next week or two.

Should have bought 4x4 material instead of 4x6 but I can cut them down easily enough. Gotta rebuild the bottom form but that's OK, I didn't really like the last one I made.

And now you have an excuse to make skis. This kids will have to have skis!

Totally agree

1st board finally out of the press! And let me tell you it is a total POS. Not really a surprise but I at least hoped to ride it. Not happening. Didn't even bother to clean it up other than running it through the band saw. I screwed up the epoxy by mixing it by volume instead of weight. Oops. It's so brittle it would fly apart on the way down. Either way it was a lot of fun to build and was 6 or 7 years in the making. Proof positive no matter how much you think about and read about something, there's no substitute for experience. A great many things were learned on this one, which was basically the idea anyway. I have a new one started in the background and looking forward to getting it done.

I also ended up moving everything I could into the basement for the winter. I just can's afford that much kerosene to keep the garage warm.

Right on dude. I can't wait to see more. Keep the pics and updates coming.

What epoxy are you using? What is the differences between the weight ratio and volume ratio? I would think you would have added more hardener than you should have so it kicked faster. Which is okay as long as you got it in the press before it this happened. How long did your layup take?

"Proof positive no matter how much you think about and read about something, there's no substitute for experience"

I'm living proof of that one... ;-)

Dude, mount it and ride it. Who cares if it's a total pile, it's not going to break on you. One run won't hurt, I bet you'll be surprised at how capable it is.

Great that you're already working on #2, you gotta stick with it!

Looks like there are some seriously major dry spots in the tip and tail? Are those delams, or just totally dry spots?

Improper ratios with most epoxies won't cause it to "overcure" and turn brittle, nor will it speed it up. An improper ratio will result in a weak cure, it'll be soft, and take longer, even if you use too much hardener. Brittle epoxy might mean it was cured too hot. A polyester resin is different, and will cure faster, hotter, and more brittle with more "hardener" (catalyst). But we don't use polyester resins with skis/boards, we use epoxy resins (nearly everybody anyways)

What kind of resin are you using?

Using Forrest Paint. 218S000 with 212K001 hardener. Those are indeed delams. The base also delammed from the core so going down the hill would be like riding a ram scoop. I had to take it off the press early because my shop lost heat and I tried to "save" it by getting what I could into the house. I think I'll make some heat blankets in the near future.

Probably didn't get a full cure before you cut the flash thus the delam.
If your epoxy was hard when you brought it in the house it might have been ok if you left it a week or so before you cut it.
Not sure about the new forrest #s but I know QCM's room temp cure stuff took close to a week to reach full cure without heat.
Just cause it's hard doesn't mean it's fully cured.

Buy a half decent scale and always mix to manufacturers ratio.
As twiz said too much hardener will react similar to too little.
Any excess of either resin or hardener will not chemically bond.
You end up with a sticky mess and it will never harden.

Sad to see your failure but keep at it.
Even with a few successes under your belt you'll still find "it's always something".
Chalk it up as a learning experience and try again and again and again...

You can probably repair your delams with a little epoxy and some clamps.
One thing I have learned is, if you can build a ski/snowboard you can surely fix one

sam

Yeah, I'm going to let it sit for a while and see if that takes out some of the brittleness. If it gets better ill try a repair. Though I'm not in much hurry to do so as I already started the next one. And I'll probably have that one pressed first. But yeah I think leaving it alone for a while before cutting is a good idea.

Just to make sure you did clean and dry and flame treat the uhmw in the layup?
The improper amount of hardner most likely led to the poor bond but that resin is a room temp cure epoxy system?

According to the rep it will cure at room temp but isn't optimal. She was unable to be more specific on what "not optimal" means.

Most likely means is less repeatable and doesnt reach the full mechanical spec carachteristcs of tensial and total strength.
within 5-8%of spec prolly.
mixing weight to volume is a huge difference.
20 buck digi scale on ebay and done.

Don't trash the board. I've used skis that were "less than perfect" to test/practice repairs and use them in What If situations. You can buy a digital scale for less then $20 at Costco, well worth it. I use it all the time and also have a printed chart of mixing ratios next to my scale in 2oz increments.

Harbor Freight also has very cheap digital scales. Get a scale and a pack of keg cups for mixing.

I'm really curious about the description of "brittle". What is it about the board that seems brittle? If you flex it, does it crack? It's a composite, so it's not like it will shatter if dropped.

Also on your tail (the bottom of the full length photo) I see two horizontal lines on the tip spacer that look like maybe they had concentrated pressure there. I see you're using a cattrack, are those marks from some of the cattrack bars? Do you have any kind of material between the cattrack and the laminate (i.e. sheet metal)?