Ski Builders Forum

ANY BODY USING WOOD FOAM?
ON SECOND PAIR RESULTS WERE GOOD BUT LITTLE TOO STIFF
183 CM LONG
TIP 135MM RAW CORE 3.8MM THICK AT LAST SNOW CONTACT AREA

WAIST100MM RAW CORE 12.6 MM THICK UNDER FOOT

TAIL 120 MM RAW CORE 4.4 MM THICK AT LAST SNOW CONTACT AREA


CAP CONSTRUCTION----- SIDEWALL OF CORE 20 DEG ANGLE
NO CAT TRACK BUT USED 40 DUROMETER RUBBER 1/4"THICK UNDER FIREHOSE TO SQUISH AROUND SIDEWALLS
USED QCM EPOXY
200 DEG TEMP @1.5 HRS BOTTOM HEATING
USED 3/8"WIDE VERT LAMINATIONS FIR/FOAM/ASH
USED 15 LB FT SQ DENSITY SIGN SHOP FOAM---------EXPENSIVE --(THIS IS CLOSED CELL FOAM THEY ROUTE AND CARVE FOR SHAPED SIGNS . TO GIVE AN IDEA --IT WILL COMPRESS OR PERMANENTLY DENT ABOUT 0.007" USING A ROUND FLAT FACE 1/4"DIA STEEL PUNCH @25 LBS PUSH
USED RUBBER VDS FULL ACROSS BOTTOM 22 0Z TRIAX S GLASS BOTTOM NEXT--1/8" WIDE CARBON STRIP IN CENTER TIP TO TAIL AND TWO MORE 24" LONG CARBON 1/8" WIDE EACH SIDE OF CENTER STRIP AT TIP AND TAIL ----NEXT----THEN FOAM /FIR/ASH CORE ---NEXT 5 OZ 45 DEG KEVLAR --NEXT -THEN 5.7 OZ 45 DEG CARBON LAYER NEXT TOP LAYER IS 5 OZ 90/90 DEG KEVLAR
SKIED 20-30 " FIRST TRACKS FRESH BUT HEAVY SNOW IN VERMONT NEXT TO BUDDY ON ANTIPISTES
REBOUND WAS GOOD EXELENT IN 12"DEEP WHERE GROOMER KNOCKED IT DOWN THE NIGHT BEFORE BUT WHEN IN THE REALLY DEEP STUFF ----HAD TO STAY IN THE BACK SEAT WHEN BACK FOOT WANTED TO TIP DIVE DURING TURNS

WILL TRY ANOTHER NOT SURE TO ADJUST CORE PROFILE THICKNESS TYPE AND AMOUNT OF EPOXY OR BOTH

ANY INPUT?

First off STOP YELLING.
Second, 4mm is pretty darn thick, I can bet it is stiff.
The thickness of your core is giving you your stiffness.
More epoxy will make it brittle and heavier, more glass heavier.

Would like to see pics of your core.

sam

what is your weight per ski in grams?

This is a strange asymmetric composite layup. Thought that was bad with a single side heat source.

What are you trying to gain in compression with the kevlar?

You have an asymmetric layup about your core with your composites. With a single bottom heat source you can get the bottom layer to cure before the top and with different composites you can get camber changes and variations from ski to ski if you do them on at a time.
Doubt its much of a problem with a core that thick.


Never heard of kevlar absorbing water but its hard to wet out in the layup from what I here.

Yo Wingworks, I would like to here more on the "Cap Construction" with your press, very interested in trying to pull that off. On your stiffness problem, I do my cores with 2/3rds poplar, with 1/3rd. bamboo (bamboo on the outside, sidewalls) and good dimensions for me are .380 to .400 in the center, with a linier taper to .080 at the tip and tail. Works for me....KT

I have thought about using foam in my cores too. I was going to router voids in select locations so not to interfere with bindings then inlay XPS trimmed to suit.

I'm not really concerned with performace charicteristics of the foam, it's the adhesion that concerns me.

Has anyone used XPS? Or have any comments regarding adhering to foams.

Cheers,

Wingworks - Post some pics, would like to see the ski. I can see why the ski was stiff, the core/tip/tail is fairly thick to begin with, then you added in 22 oz., glass, Kevlar and carbon.

Speaking of foam, a friend of mine builds ski chairs. I was over there today and he had some skis cut up. Interesting to see what they were putting in skis 10-15 years ago. He has a Dynamic ski that had a small narrow wood core encased in black foam. Pretty dense stuff. The overall core was fairly thick. Don't know what the foam actually is. I'll see if I can take a pic during the week and post it.

Also other interesting cores were Atomic ( I think). Basic wood cores with thin wood vertically laminated, cap construction. Then in the bottom of the core they cut 3 or 4 thin grooves out of the core. I don' know what that would do other than lighten the ski, make it little softer.