RightSideways Skis

Document your personal work here. Show photos, movies, and share your secrets.

Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp

rightsideways
Posts: 51
Joined: Mon Apr 15, 2013 4:59 pm
Location: Breckenridge, CO

Ski # 6 - clear top and bottom

Post by rightsideways »

After making the camo skis i thought it would be cool to make just a clear topsheet, clear base ski to see how they turned out.

the shape was: 125-99-111 and based heavily on the DPS wailer in terms of taper at the tip and tail. I was going for a standard no carbon layup with a core profile of 2-12-2 with 30 cm of flat underfoot centered 55% back on the ski... unfortunately, my profiler rails were a bit off so i ended up with ~2.25-10.5-2.25. I was worried about the skis not being stiff enough so the layup went:

base
edges
vds
22 oz triax longitudinal away from core
core (oak/poplar 3/4" laminate) with two strips of 24k carbon tow sort of diagonal (waving this way and that on the ski, but mostly in the right direction) on either side.
22 oz triax longitudinal away from core

my mold setup was 400 mm tip rocker (eyeballed so i don't know what the radius is) 105 cm camber underfoot w/ 5mm camber and 300 mm tail rocker. the way I set up the camber mold was a little different than I have been doing. I used to profile the camber out of 3/4" MDF, flat bar / sand away any giant ripples or inconsistencies and then the 1/8" hardboard would go on top. I was noticing random edge high, base high variations that i figured were related to the mold not being perfectly smooth so the way I do camber now is:

profile the camber out of MDF so that the front and back have a final height of 1/4". then i lay a piece of 1/2" MDF on top. the tip and tail MDF ribs have a minimum height of 3/4". hardboard sits on the combination. the bases were a bit more uniform in edge highness this time.

I like the way they turned out:
Image
bases out of the mold
Image

Image
inserts for tele and AT

Image
camber

Image
see that wavy carbon.

Image
mounted in the only clean room in the house (recently remodeled upstairs).

I skied them for the first time in the backcountry and they were great. I went to a resort the next day and skied some icy moguls and loved them! I have a new pair of favorite skis. Next I need to mount the tele bindings on and see how they go with a free heel.

i should probably get back to the house work, but, the skis are way too much fun. my next project are Mahogany veneer covered boards with patina'ed copper inlay called "Mahogany Run". first i need to sort out my core profiler once and for all (better vacuum design, metal rails w/ adjustability).
rightsideways
Posts: 51
Joined: Mon Apr 15, 2013 4:59 pm
Location: Breckenridge, CO

new pair in the press

Post by rightsideways »

FINALLY I have some time to build skis. I just put my house on the market, and I'm done with renovating, and it's time to build some skis.

first, some improvements:

Image

Image

Image


enhanced vacuum table which is used for core and camber mold profiling

I like this table better than the other one, although It still doesn't hold the boards down perfectly at the tip/tail area so I'm just nailing the core/camber blank to the table with a brad nailer at the tip/tail.

the extruded aluminum track, beneath the MDF, is going to be used in a future infinitely adjustable rail system, which I probably won't work on for a while because I'm moving to Colorado. for now i'm just cutting the guide rails, for the router, out of wood.

my first new pair of cores was profiled at just under 3 mm to 11.5 mm in a linear taper where the maximum thickness was placed at both the center of camber, and narrow point in the sidecut.

core specs:
3-11.5-3
poplar only, no sidewalls - core extends to edge of ski

layup:
green UHMW base
rubber along edges
22 oz triax (longitudinal facing away from the core)
core
22 oz triax (longitudinal away)
mahogany veneer (quartersawn)

final ski figures:

143-112-127 with 350 mm tip rocker. I put 8 mm camber underfoot. I will measure everything when I remove the flash next week.

I used mold release wax on top of the hardboard underneath the bases, and parchment paper on top of the veneer, and under the top layer of hardboard, then maple cat-track and bladders.

we'll see what they look like tomorrow when I pull them out of the press.
gav wa
Posts: 381
Joined: Tue Feb 18, 2014 8:58 pm
Location: Perth

Post by gav wa »

Have you sealed that mdf with something? MDF is so porous it can be used on a vacuum table without grooves or holes. You will be losing a lot of vacuum through the sides of you mdf if you don't seal it up well. I have found the coated mdf used for cupboards and stuff is goid for vac tables
rightsideways
Posts: 51
Joined: Mon Apr 15, 2013 4:59 pm
Location: Breckenridge, CO

Post by rightsideways »

gav wa wrote:Have you sealed that mdf with something? MDF is so porous it can be used on a vacuum table without grooves or holes. You will be losing a lot of vacuum through the sides of you mdf if you don't seal it up well. I have found the coated mdf used for cupboards and stuff is goid for vac tables
I painted a thin layer of poly on there, but, it doesn't really seem sealed looking at it. I'll look into coating with something different though thanks!
pmg
Posts: 479
Joined: Sat Dec 01, 2012 8:59 am
Location: Sonthofen

Post by pmg »

If the epoxy you are using is liquid enough, just coat it with epoxy.
rightsideways
Posts: 51
Joined: Mon Apr 15, 2013 4:59 pm
Location: Breckenridge, CO

Post by rightsideways »

pmg wrote:If the epoxy you are using is liquid enough, just coat it with epoxy.
I will do that, I think MAS is liquid enough, but I have a new problem... The center of the table is more than 1 mm lower than the sides due to a small amount of droop in the MDF. My manifold is pretty low but I need to reinforce the table better, as well as seal it. The cores i just profiled are about 1 mm different over the six inch width after profiling. no bueno.

Good thing I've got some credit with the depot... I think I can slide some metal in there and stiffen it up a bit.

on a positive note, my skis came out of the press this morning, and they look pretty good.

Image

Image

waiting to remove the flash is the hardest part.

With my next pair I'm going to experiment with some inlays. The veneer isn't paper backed so I'm going to try and keep it simple because it's really fragile. With every new pair, I struggle for hours, and days, over what to change about the structure of the ski, and what to keep constant in each new pair of skis. It seems impossible to change one variable at a time without affecting many different properties. Although, with the lack of precision I'm getting with my tools, and woodworking skills, I probably shouldn't worry, and just play around to gain experience building.
User avatar
skimann20
Posts: 345
Joined: Wed Feb 27, 2008 8:28 pm
Location: Taxachusets

Post by skimann20 »

rightsideways wrote:With every new pair, I struggle for hours, and days, over what to change about the structure of the ski, and what to keep constant in each new pair of skis. It seems impossible to change one variable at a time without affecting many different properties. Although, with the lack of precision I'm getting with my tools, and woodworking skills, I probably shouldn't worry, and just play around to gain experience building.
exactly... If these things didn't cost so much to build it would be a hell of a lot easier to only change one variable... I've even considered putting my data into our statistical tool here at work to try to cut down the guess work. I just can't figure out how to put a rating on the "goldylocks" value. ;-) I'd say at least keep one variable the same from ski to ski.

skis are looking good. what wood is the top sheet?
gav wa
Posts: 381
Joined: Tue Feb 18, 2014 8:58 pm
Location: Perth

Post by gav wa »

Nice looking skis. Is that the green base from skilab? I think I'm using the very same stuff right now.
skidesmond
Posts: 2337
Joined: Tue Apr 07, 2009 3:26 pm
Location: Western Mass, USA
Contact:

Post by skidesmond »

skimann20 wrote:
rightsideways wrote:With every new pair, I struggle for hours, and days, over what to change about the structure of the ski, and what to keep constant in each new pair of skis. It seems impossible to change one variable at a time without affecting many different properties. Although, with the lack of precision I'm getting with my tools, and woodworking skills, I probably shouldn't worry, and just play around to gain experience building.
exactly... If these things didn't cost so much to build it would be a hell of a lot easier to only change one variable... I've even considered putting my data into our statistical tool here at work to try to cut down the guess work. I just can't figure out how to put a rating on the "goldylocks" value. ;-) I'd say at least keep one variable the same from ski to ski.

skis are looking good. what wood is the top sheet?
My 2 cents... Work with a single ski design that you like. Then start tweaking or trying different layups and materials. Keep detailed notes or a spreadsheet and that will help you figure out what works and why. Also I found making sample layups of a standard size is a good way to determine if something will work or not. In doing so you can compare sample 1 to sample 2 recording each of their characteristics. Bend, twist, and break each sample noting the force it takes to do each task. It's a lot cheaper that way too.
rightsideways
Posts: 51
Joined: Mon Apr 15, 2013 4:59 pm
Location: Breckenridge, CO

Post by rightsideways »

skimann20 wrote:
skis are looking good. what wood is the top sheet?
thanks! it's quartersawn mahogany veneer. not paperbacked, just something that was pretty cheap on veneersupplies.com
gav wa wrote: Is that the green base from skilab?
yep, those are the skilab green bases. they're pretty neat looking, and when the skis are laid up they're sort of translucent so you can kind of see the core through them.
skidesmond wrote: My 2 cents... Work with a single ski design that you like. Then start tweaking or trying different layups and materials.
I agree, I am tempted to try a fatter outline two pairs from now. but, I like that idea. so far I've been trying to add some small detail to each layup. That gives me something new to learn, but, I don't overwhelm myself with a bunch of new techniques during the layup. However, keeping the same outline and mold makes each successive ski much less labor intensive.

Next pair will be the same mold, same outline, and a bit thinner core along with some copper and mahogany veneer laid up on the topsheet.
User avatar
vinman
Posts: 1388
Joined: Fri Nov 09, 2007 4:16 pm
Location: The tin foil isle
Contact:

Post by vinman »

the copper veneer from veneer supplies is coated with wax, no bueno for bonding. You can only get the larger sheets without wax.
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com
rightsideways
Posts: 51
Joined: Mon Apr 15, 2013 4:59 pm
Location: Breckenridge, CO

Post by rightsideways »

vinman wrote:the copper veneer from veneer supplies is coated with wax, no bueno for bonding. You can only get the larger sheets without wax.
I used to use heptane or hexanes to get mineral oil off of round bottom flasks. Maybe mineral spirits followed by acetone after a gentle heating will remove the wax... Thanks for he heads up! I just got one of the patina copper samples so it probably has the wax on there.

It's only a top sheet so I think the worst case scenario is it peels off and leaves a gap that exposes the core. That might also look cool. I need to find some of that medical tape to hold everything together during layup.
rightsideways
Posts: 51
Joined: Mon Apr 15, 2013 4:59 pm
Location: Breckenridge, CO

copper veneer

Post by rightsideways »

another pair slammed in the press. same shape dimensions as the last pair. poplar core 2-11-2 with 11 @ 55% back from the tip and placed at boot center. linear core taper w/out a flat spot.

layup:

black ptex base
rubber
22 oz triax longitudinal against core
core
22 oz triax longitudinal against core
mahogany veneer with patina copper inlay

laid up w/ the usual 0.45:1 by weight MAS medium hardener. r.t. cure at 40 psi

I prepped the copper by heating w/ a heat gun, wiping thoroughly with mineral spirits followed by acetone and then sanding with 220 grit using an orbital sander. I held the topsheet conglomeration together in a way that I probably won't do again. Instead of tape, I used carbon tow and epoxy to hold everything together temporarily. I heated the epoxy so it would kick quickly and I could get the layup done today (didn't think I had any medical tape). Unfortunately I didn't get any pictures, but, I don't think it matters 'cause next time I'm using tape.

We'll see how the whole thing comes out. crossing my fingers that the topsheet isn't crap. These are for my bro for helping out with the house.

Speaking of the house, we have the appraisal tomorrow at 12:30. Hopefully I'll have the skis out before then, otherwise the appraiser is going to wonder what the hell that steel press is all about.

also, here are some pics of the last pair:
Image

Image

Image
User avatar
vinman
Posts: 1388
Joined: Fri Nov 09, 2007 4:16 pm
Location: The tin foil isle
Contact:

Post by vinman »

Nice looking skis. You can make your own copper patina with some amonia and salt in a sealed container. Lots of other patina recipes on the net if you search.
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com
rightsideways
Posts: 51
Joined: Mon Apr 15, 2013 4:59 pm
Location: Breckenridge, CO

Post by rightsideways »

vinman wrote:Nice looking skis. You can make your own copper patina with some amonia and salt in a sealed container. Lots of other patina recipes on the net if you search.
Thanks! I will patina my own going forward. If the copper patina in these skis peels away I can fix it with my own!

I just pulled the pair out of the press and there is one major issue with the edge wrap on one of the tails:

Image

I'm wondering if it's possible to grind away the epoxy filling that space, add some new epoxy and then bang the edge back in place, or, if that will only make things worse. It's not an effective edge so I could just grind it down and run it, but, it'll look pretty bad. I'll do a skibuilders search because I guarantee this has happened before...

here's another pic:

Image

I can't wait to cut these out. Next up, mahogany stringers w/out any graphics on the topsheet. I'll probably use the same mold one more time before going full banana ski for my super wide pair.

quick question: I've toyed with the idea of using some sort of clear plastic tipspacer w/ a clear base in the tips and tails for a see-through ski. has anybody had any luck with this? a quick search hasn't resulted in anything. I can get clear PETG from mcmaster: http://www.mcmaster.com/#85815K12

any thoughts?
Post Reply