sammer 2011/12

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

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sammer
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Joined: Wed Dec 19, 2007 10:37 pm
Location: Fernie B.C.
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Post by sammer »

Bit of an update and more progress.
Weather was OK today so got some time to cut out a few pairs, well almost, ran out of daylight so still one PORTLY left to cut out.
All still need sidewalls beveled and sanded. Bases still new to be ground.

Starting with the daughters new skis,
142cm 130-97-120 12m radius.
Rockered tip and tail slight camber under foot.
Once again I had a bit of core bridging. Kids skis are so short with such an abrupt taper they don't flex into the mold like longer skis do. Thought I'd learned that last pair.
You can just see the "treefrog" stenciled on the core, thought the white cotton would go clearer.
Shown here in comparison with her old 130's. Probably hang on to these as the new ones are probably too fat for the hard groomer days, we'll see.

Image

Next Whizzer for piste, Dark green on left
All mountain carving ski and my first using bamboo.
183cm 140-92-125 17m radius, Fairly stiff flex
Cores are just shy of 3mm at tip and tail so an obvious line where they join.

Image

Next Portly a big 180, 23m radius.

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Shot of the bases "treefrog" turned out looking pretty good. Waiting to see what it looks like after a base grind.
Flouro green base is fairly translucent and shows everything thru it.
looks blotchy but a base grind might clear that up I'll keep you posted.

Image

Now the issues...
Portly's cores were a bit wider than I would normally make so over hung the base and edge a fair amount.
Once the vacuum pulled it into the mold the cores cracked near the side wall joint and tipped up.
I was able to open it up and put a bit of tip spacer under the over hanging bit but by that time the epoxy was starting to gel and I couldn't get it to sit back down flat.
This left a weird little line you can see in the second photo near the right edge.
Will not effect the ski but still a cosmetic issue that would relegate this ski to second status.
I switched to a lighter poly to put on top the layup to keep the epoxy off my vacuum membrane,. This has solved the issue of creases making marks on my top sheet shown earlier.

Now on to the next.
Layed up the reverse reverse ski yesterday.
Cut it pretty close running out of hardener and having to stretch it a bit.
Everything wetted out OK and this is what it looked like in the press.

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Rocker looked pretty good in the mold but slumped quite a bit when it came out. should still have a bit more than the last pair.

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Hope to get the last portly and the MOFO's cutout soon.
Then it's off to JV's shop to base grind. (grindrite is still there as it won't ever get down in the dungeon) Bolt on some binders and pray for snow!

Still have 1 set of cores left, the repaired one is waiting to build another Portly. See if I get time this year.
Back to work end of next week.
Ski building has been my physio therapy :D

Later

sam
You don't even have a legit signature, nothing to reveal who you are and what you do...

Best of luck to you. (uneva)
troublemaker
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Location: The Dalles Oregon

Post by troublemaker »

What kind of vacuum membrane is that? Looks like it conforms well.
skidesmond
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Post by skidesmond »

Nice job Sammer!
ben_mtl
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Post by ben_mtl »

Great job Sam ! can't wait to see those MOFO ! ;)
A bad day skiing is always better than a good one at work...
sammer
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Joined: Wed Dec 19, 2007 10:37 pm
Location: Fernie B.C.
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Post by sammer »

Troublemaker it's PU.
Got it here...
http://www.veneersupplies.com/products/ ... erial.html
Had to thermo-form it a bit at the tall tip and tail molds but other than that it is really stretchy!

Thanks guys.
Ben, I cut out the MOFOs today just before the rain so still need to bevel and base grind. they look pretty good, will try to get pics up later today.
they definitely lost a bit of rocker. I cured them pretty fast with top heat only so I think that is the primary cause of the camber change.

Carbon fiber takes a bit of a drift off the edge of one tail but shouldn't affect the ski. Once again a cosmetic flaw :(

sam
You don't even have a legit signature, nothing to reveal who you are and what you do...

Best of luck to you. (uneva)
Smiley
Posts: 14
Joined: Sun Feb 05, 2006 8:35 am
Location: Switzerland

Post by Smiley »

sammer wrote:Troublemaker it's PU.
Got it here...
http://www.veneersupplies.com/products/ ... erial.html
Had to thermo-form it a bit at the tall tip and tail molds but other than that it is really stretchy!

Thanks guys.
Ben, I cut out the MOFOs today just before the rain so still need to bevel and base grind. they look pretty good, will try to get pics up later today.
they definitely lost a bit of rocker. I cured them pretty fast with top heat only so I think that is the primary cause of the camber change.

Carbon fiber takes a bit of a drift off the edge of one tail but shouldn't affect the ski. Once again a cosmetic flaw :(

sam
Sammer,

What do you think of the PU? You think you will get a lot of presses with it? Looking for a high quality vacuum material and found these guys:

http://www.columbus-tech.com/en/671120/ ... rview.html

But it is super expensive. Guy quoted me nearly 600 euros for a bag 300cm x 65cm....

Do you have a vacuum table or bag? I am looking to set up a table with a lid that the vacuum material is attached to, some sort of weather striping on the base table, clamps to hold the lid to the table, air flow channels in the base table etc...
Not All Who Wander Are Lost
sammer
Posts: 933
Joined: Wed Dec 19, 2007 10:37 pm
Location: Fernie B.C.
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Post by sammer »

Smiley wrote:
Do you have a vacuum table or bag? I am looking to set up a table with a lid that the vacuum material is attached to, some sort of weather striping on the base table, clamps to hold the lid to the table, air flow channels in the base table etc...
I've been using this for quite sometime.
Membrane in the pic is nylon, worked OK but needed to be heat molded a fair bit and held its shape.
The PU is better but still had to be heat molded for the tip and tail molds.
I've pressed 6 or 7 pair of skis so far but have to use the same mold as the PU is now formed to that specific shape.
If I had the money I'd go with silicone but that stuff is really expensive here.
If you keep the epoxy off the PU it should last a long time. Epoxy sticks to it really well!

Image

When I built the table I thought about making an elaborate vacuum system but then said why? and did this instead.

Image

The wood block has a couple holes in one side and a handful of saw cuts on the other. Vacuum pressure is equal all around the mold as the bag can't conform to the junction between the mold and the table.

sam
You don't even have a legit signature, nothing to reveal who you are and what you do...

Best of luck to you. (uneva)
Smiley
Posts: 14
Joined: Sun Feb 05, 2006 8:35 am
Location: Switzerland

Post by Smiley »

sammer wrote:
Smiley wrote:
Do you have a vacuum table or bag? I am looking to set up a table with a lid that the vacuum material is attached to, some sort of weather striping on the base table, clamps to hold the lid to the table, air flow channels in the base table etc...
I've been using this for quite sometime.
Membrane in the pic is nylon, worked OK but needed to be heat molded a fair bit and held its shape.
The PU is better but still had to be heat molded for the tip and tail molds.
I've pressed 6 or 7 pair of skis so far but have to use the same mold as the PU is now formed to that specific shape.
If I had the money I'd go with silicone but that stuff is really expensive here.
If you keep the epoxy off the PU it should last a long time. Epoxy sticks to it really well!

Image

When I built the table I thought about making an elaborate vacuum system but then said why? and did this instead.

Image

The wood block has a couple holes in one side and a handful of saw cuts on the other. Vacuum pressure is equal all around the mold as the bag can't conform to the junction between the mold and the table.

sam

Looks good Sam. That is essentially what I plan on building. Is your lid frame made of MDF? What about the base? Looks like formica maybe? Did you just use a standard weather stripping on the lid frame and does it hold the vacuum well? Sorry for all the questions, but I have limited experience with vacuum systems and want to get it (mostly) right the first time. If you think Canada is spendy come to Switzerland!!!
Not All Who Wander Are Lost
sammer
Posts: 933
Joined: Wed Dec 19, 2007 10:37 pm
Location: Fernie B.C.
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Post by sammer »

Got the last few skis cut out.
Couldn't wait and peeled the protective film off one of the MOFO's. Curiosity got the better of me :)

The socrep is very shiny you can see the fluorescent lights in the ski on the right, the one on the left still has its film.

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Here is a good representation of the difference in clarity between the durasurf on the right and the socrep on the left.
The carbon tow is under a layer of glass on the Ballista but the wood core and glass are way more visible on the MOFO.

Image

Here you can see the carbon tow drifting off the side of the tail.
Didn't think I'd have enough epoxy so left the carbon out during the layup.
Would normally have put it right on the wood core and lined up better with the stringers.
Ended up putting it right under the topsheet at the last minute.

Image

Here's a group pic of some from this year and a few from the past.

Image

Later

sam
You don't even have a legit signature, nothing to reveal who you are and what you do...

Best of luck to you. (uneva)
sammer
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Post by sammer »

Smiley wrote: Looks good Sam. That is essentially what I plan on building. Is your lid frame made of MDF? What about the base? Looks like formica maybe? Did you just use a standard weather stripping on the lid frame and does it hold the vacuum well? Sorry for all the questions, but I have limited experience with vacuum systems and want to get it (mostly) right the first time. If you think Canada is spendy come to Switzerland!!!
Press frame idea and plans came from here
http://www.joewoodworker.com/veneering/ ... -press.htm

Used maple for the frame, table top is 3/4" particle board with a laminate (formica) on both sides. 2 sheets of 3/4 mdf under it all to keep it twisting/warping.

Mdf would not have enough strength for the frame. The vacuum is very strong and makes my 8' long frame members pull in a good inch or more.
Looking from the top down it resembles an hourglass. The wood block where the hose attaches has 1/2 of play on either side at rest but touches once under full vac.
All the materials except to wood and screws came from joes site.

Needs a couple clamps to hold the frame down when 1st starting to suck but after reaching full suck can be removed if necessary.


sam
You don't even have a legit signature, nothing to reveal who you are and what you do...

Best of luck to you. (uneva)
troublemaker
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Location: The Dalles Oregon

Post by troublemaker »

"If I had the money I'd go with silicone but that stuff is really expensive here."


I have been thinking about making a fiberglass reinforced vacuum bag out of the same silicone I use for heat mats. I have a gun that I think can spray the silicone out of. Pretty much spray the silicone onto the ski mold and build it up to about 3/16" of a inch. I can get 9 pounds of silicone for about $75, and that should be enough to build a bag.
sammer
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Post by sammer »

I've been thinking along similar lines using my vacuum bag to make a silicone vacuum membrane.
I've got enough PU for 1 more membrane so not a problem for a year or 2 but when the time comes I might have to give it a try.
It would have to be clear though as I like to see the air and shifting when the ski is pressing.

sam
You don't even have a legit signature, nothing to reveal who you are and what you do...

Best of luck to you. (uneva)
sammer
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Post by sammer »

Got bases ground yesterday.
Tons of fun shot a ski across the room using a brand new 120grit ceramic belt. That sucker was grippy and ripped the ski right out of my hand :oops:

Found an issue with the girls skis.
The core bridged pretty good on one tip.
NEED MORE PRESSURE! (or a least pay more attention to fit)

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Left a void between the base and core. when grinding the plastic warped out and ground off really fast. Of course I didn't notice it the first couple passes 'cause it wasn't thru yet.
Its a pretty big blister.

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Gonna get a syringe and try to squirt some epoxy under it for the time being. Might have to cut it out at some point though.

Camber on the MOFO's turned out better than I thought.
Compared to last years reverse skis which were pretty flat.

Image Image

And bases look pretty good. Don't have much of the swirl base so mixed it up a bit.

Image

Still have sidewalls to finish and edges to file, I hate filing edges, ( might have to build an edger :)


Later

sam
You don't even have a legit signature, nothing to reveal who you are and what you do...

Best of luck to you. (uneva)
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Dr. Delam
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Location: Truckee

Post by Dr. Delam »

I've found that some topsheets are super slippery so I always keep my hand behind the end of the ski and keep it flowing through.

A mini drum sander is what I use when I want to put a quick edge on my skis if I don't have time to go to the shop. One of these days I'll buy a tilt base router so I don't have to switch out my shims. http://www.harborfreight.com/20-piece-s ... 42006.html


Image
skidesmond
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Post by skidesmond »

Dr, that's a good idea with the drum sander. There are machines you can buy (hundreds of $$$) that are made just for that. They have ceramic stones, guides, tilt for 0-3 degrees, etc. But it's basically doing the same thing you're doing. I started shopping around for a round stone. I'm sure Dremel must make something.... Put that on my list.
Last edited by skidesmond on Wed Nov 28, 2012 3:57 pm, edited 1 time in total.
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