Ski Builders Forum

never leave your compressor plugged for about 4 weeks unobserved. loosen screws may result in oil loss that causes a dry run with several hundreds euros of damage.
watching out fpr spare parts i recognized what a financial investment that good old german kaeser is... or was.

If (hopefully When) I get to pressing, I'm going to reread this post for sure! Good "don't do"s in here.

don't have the overhead light providing all your illumination blow during layup!

Expect that the electricity will go out as soon as you get a ski in the press... and that your generator won't want to start up.

Oh that would suck. I'm contemplating whether I should press a pair this weekend with a storm/hurricane on the way. Maybe hold off till the storm passes.

Hey guys, great thread! LONG time lurker (years). This post will be most helpful for newbies (if anyone), and my apologies if it comes of preachy, just trying to help.

Pre heating your resin is a really good practice for many reasons, but can certainly be a tricky one to execute with repeated sucess (like so many other aspects of ride building).
Every supplier, be it qcm, entropy, etc... will be able to tell you at which temperature their/your resin reaches it's best working viscosity. If you cannot discern it from the data sheets, just contact them and ask 'em.
Most of your comercial composite houses keep their resins at this temp. Hardener is a different story, you want to keep that "cool" and as pointed out earlier in this thread, once you introduce the two (whether your resin was pre-heated or not) you want to keep you batch as small and thin as possible.
When I started with this process I used an old electric fry pan, added a few cm of water, and kept the temp low (between 90 - 100 F). I would then place my next batch of resin in a disposable pie tin and set it afloat on the warm water. When your ready for your next mix you grab the tin, add your hardener, mix and go, being sure to place the next batch of resin in the warm water.
The aluminum pie tins are good conductors, and really shallow, which does make mixing the batch a little challenging, but will keep the batch from cooking. I've also tried placing the whole 5 gallon bucket of resin in a work sink filled with hot water. It all works, and there are plenty of ways to get there. Anyone who has done it can tell you how beneficial this is when trying to wet-out your media.
The more you can learn about your resin, the happier you're going to be. For example, do you know what "state" you goop should be in when you ramp your blankets up to temp, and what temp your shooting for, or when to fill your hoses with air? (again, your resin supplier should be able to help you out here). All of these things play a roll in your sucess. Unfortunately, for most small builders, they lay-up/press is the process we spend the least amount of time "doing", and often becomes the thing we dread, fear, and/or hate the most.
I'm sure their are countless members of this forum who have spent untold hours building jigs, shaping their materials, etc... only to have it all go into the "fail" pile due to some lay-up/press related issue. Failing is certainly a big part of this, and will always come with certain benefits, but the more test batching you can talk yourself into doing, the happier your going to be when you finally place those 20 man/hr skis in the press.

For any newbies still reading this long winded piece (sorry), I would recommend laying up some one piece pine core "skis" first (you probably have a bunch of pine cores laying around from all of you planer jig tests, right? Haha). Maybe just start with some 10oz glass, and edge wrapped bases, leave your vds, carbon, etc... out for now. Upon sucess you can keep adding more and more "real" materials until you feel confident that what you pull out of your press is going to be a ski/board, and not just another learning experience.

Although you may think it costly to be laying up bases and edges (which I know are hard to come by in small doses) you'll be psyched when you throw those fully loaded puppies in the cooker and they come out looking lean and mean. Added benefit is you'll now have a nice amount of "practice" skis around to hone your finishing skills on.

Apologies for my long windedness, just trying to help. Anyhow, a very sincere thank you to all who have posted and shared on this site, the value of your shared experiences is immeasurable. Heading back into my hole now.

...and SHARP blades in your planer, if you use it for profiling cores! (delamination can come unexpectedly ...)

How about getting your toolpath cut depths wrong and plowing a hole right through the core and into the cnc table when your trying to cut pockets for the base of the inserts.

how about grinding grinding grinding, doing whatever i can to get this base flatter and get those tiny pockets of resin out near the edge, man this board didn't press out so flat... ah damn in the mean time our grinder is termpermental, and just ate another belt... shit there goes the 60dollar trizact belt too... spending an hour grinding one board and still have a couple dimples... give up its just a test board anyway...

only to go back to crowns site, and cdw site, on a hunch... to realize i did my math wrong and i bought an entire roll of base that's a few thousandths too thin

how about grinding grinding grinding, doing whatever i can to get this base flatter and get those tiny pockets of resin out near the edge, man this board didn't press out so flat... ah damn in the mean time our grinder is termpermental, and just ate another belt... shit there goes the 60dollar trizact belt too... spending an hour grinding one board and still have a couple dimples... give up its just a test board anyway...

only to go back to crowns site, and cdw site, on a hunch... to realize i did my math wrong and i bought an entire roll of base that's a few thousandths too thin

At least you didn't grind all the way through the base!

did that too, on a customer's board that we had just repaired!!!
it delammed so they brought it back, adn we added epoxy to the delams and re-pressed it, came out sick, i had to grind off the excess epoxy and i went right thru it... we had to give them a brand new board, and i got to keep the mistake for my own.

this was when i worked @ a factory, i could list 100 ways i've screwed up, from mis-drills, to too thick or too thin core profiling, to bad flame jobs, wrong size inserts causing dimples/wrinkles, to leaving the pressure too high causing a press frame to bust apart!!! Oh and pressing a nut thru a 1000 dollar heat blanket really sucked too.

Just cut out my buddy's skis and found that 1 core had shifted about 2-3 mm. We are trying to salvage this ski but not sure it will work. We basically used the remaining flash as a moat. I abraded it with a utility knife anx wire brush and flamed it some then backfilled it with epoxy and heat cured it. It filled in fairly well but who know what this will do when we profile the sidewall or if it will hold together on snow. The other ski came out great. This is my first serious failure and it's pretty disappointing especially since i was building for someone else. Hopefully our fix will hold.

i found with core shift as well not only will the flex be affected but the ski will be twisted or racked slightly not allowing it to lay flat.

Yeah I figured there would be other problems. By my best guess on of the base pins may have come loose. Or since this is the same ski with base pins too long maybe there was some slippage induced due to this.

The epoxy has seemed to cure and fill nicely. I'll let it cure more overnight and then cut and profile them.