No, I spaced the oxidizing. I had planned to flame it. Is there a chemical oxidiser option?e wrote:Tip/Tail delam, not sure if you did this, but did you oxidize the pe after sanding?
HOSE-MAN's JOURNAL - chronicling my ski build
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
Here is a Quicktime LINK or Windows Media LINK to a video I edited together of the Nice Kilt's maiden voyage. I'm in the red jacket & am using the Kilts. The blue jacketed telemarker is on the Pocket Rockets of identical dimension. THere are a couple of frames where you can really see the flex in the Kilts.
While they are a very soft ski, they didn't suck! I was amazed. I was really expecting them to be miserable, but in the spring corn they were a very versitile ski. I did rivet all 4 ends of the skis because some delaminatin was alread evident. There were no problems with the tips or inserts or anything. What a gas!
While they are a very soft ski, they didn't suck! I was amazed. I was really expecting them to be miserable, but in the spring corn they were a very versitile ski. I did rivet all 4 ends of the skis because some delaminatin was alread evident. There were no problems with the tips or inserts or anything. What a gas!
Wa-hoo hose-man!! Great vid and tele skiing. Are you givin' away the location of that ski day? Looked very nice. Pretty cool looking down at your boards and realizing, "Wow, I made these... and they work!", eh? What's the plan for the next pair?.. better hurry, that snow is going to be melting fast. I'm out the door right now to catch another ski day. Way to go!
Awesome Video
Hoseman,
Awesome Video, I really liked how you edited the music tracks in. Your skis looked like they worked great. If you make more videos like this in the future please share.
Awesome Video, I really liked how you edited the music tracks in. Your skis looked like they worked great. If you make more videos like this in the future please share.
Hey again hose-man,
Just returned from another great ski day on the home made skis. In an earlier post, you had asked about "chemical oxidizer" options. Basically, there are 4 different treatments that will increase the surface tension of UHMW, and therefore enhance it's bondability. They are flame treatment, corona treatment, plasma treatment, and chemical surface treatment. Corona treatment and plasma treatment are relatively expensive to set up and have some not-so-good environmental by products (like ozone generation). You can read about one example of a chemical surface treatment at www.fluoroseal.com. The oldest treatment (developed in the early 60's) is flame treatment. It went out out of vogue for a while after corona and plasma treatments came on the scene, but is making a stong comeback in mainstream industry because it is relatively inexpensive, not too complex pull off, and higher dyne levels (the measurement of surface tension) can be reached with flame treatment. So, I'd recommend sticking with flame treatment for your ski building needs. It's probably good to know, too, that flame treatment can be both over and under done, although for most ski building applications, following this sites recommendations are probably good enough. If you want to be really nerdy, you can google something like " dyne level testing methods'... and plan to stay up late. Some general info: normal surface tension of teflon is 18 dyne, untreated UHMW is 28 dyne, and maximally treated UHMW can reach slightly over 70 dyne... copper is about 1300 dyne. The higher the dyne level, the more bondable it is. I've tested the treated side of the base material that I get from Crown Plastics and it runs about 70 dyne fresh from the factory... pretty darned good. Surface treatments deteriorate over time, so keep that in mind if you plan to use an older batch of treated material... you may want to re-treat to get the dyne level back up.
This may be more info than you asked for, but you seem like the kind of ski builder that isn't going to stop at one pair of skis.
Cheers
Just returned from another great ski day on the home made skis. In an earlier post, you had asked about "chemical oxidizer" options. Basically, there are 4 different treatments that will increase the surface tension of UHMW, and therefore enhance it's bondability. They are flame treatment, corona treatment, plasma treatment, and chemical surface treatment. Corona treatment and plasma treatment are relatively expensive to set up and have some not-so-good environmental by products (like ozone generation). You can read about one example of a chemical surface treatment at www.fluoroseal.com. The oldest treatment (developed in the early 60's) is flame treatment. It went out out of vogue for a while after corona and plasma treatments came on the scene, but is making a stong comeback in mainstream industry because it is relatively inexpensive, not too complex pull off, and higher dyne levels (the measurement of surface tension) can be reached with flame treatment. So, I'd recommend sticking with flame treatment for your ski building needs. It's probably good to know, too, that flame treatment can be both over and under done, although for most ski building applications, following this sites recommendations are probably good enough. If you want to be really nerdy, you can google something like " dyne level testing methods'... and plan to stay up late. Some general info: normal surface tension of teflon is 18 dyne, untreated UHMW is 28 dyne, and maximally treated UHMW can reach slightly over 70 dyne... copper is about 1300 dyne. The higher the dyne level, the more bondable it is. I've tested the treated side of the base material that I get from Crown Plastics and it runs about 70 dyne fresh from the factory... pretty darned good. Surface treatments deteriorate over time, so keep that in mind if you plan to use an older batch of treated material... you may want to re-treat to get the dyne level back up.
This may be more info than you asked for, but you seem like the kind of ski builder that isn't going to stop at one pair of skis.
Cheers
Went skiing the other day. We did some base grinding on the Kilts to see just where the high and low spots were...... We'll we didn't wax the suckers after grinding them & they were almost like skiing with your skins on all the time. We put them away quickly & used our factory skis. It was a great day though.
It's 10 minutes long, so pull up a soft chair.
Here's a link to the low quality VIDEO (10.6MB)
and
then better quality VIDEO (46MB)
It's 10 minutes long, so pull up a soft chair.
Here's a link to the low quality VIDEO (10.6MB)
and
then better quality VIDEO (46MB)
Video
Another Great Video.
On a different note, I finally got around to installing the fittings in the fire hose you sent me and I have installed the angle iron at one end of the hose. Slowly I am getting their, however I did finish by press frame and mold. I'll post pics when everything is complete.
On a different note, I finally got around to installing the fittings in the fire hose you sent me and I have installed the angle iron at one end of the hose. Slowly I am getting their, however I did finish by press frame and mold. I'll post pics when everything is complete.
Hose-man,
Really nice work! The skis and video look great. What temps were you able to achieve in your oven?
On the tape issue: we've found that the brand of tape makes a huge difference. The better brands (3m, duck) seem to hold together better, while cheap 'office depot' specials, fall apart into a million annoying pieces. With the heated press, I've been skipping the tape since the heat melts its. Instead I've been laying parchment paper (available in the baking section of a grocery store) on the mold before lay-up. Also, a little PAM cooking spray helps with the clean up of any extra epoxy. I have to give credit for that great tip to Dan from Graf snowboards.
G-man,
great info about UHMW. Care to write a short article about material prep? What's the best way to flame treat and what should I be looking for? I've been using a Mapp torch and looking for a slight discoloration and small 'bubbling'. Not sure if this is right or not and it also doesn't work well on thin material. Do you know what industry uses to clean material prior to bonding?
thanks
-kelvin
Really nice work! The skis and video look great. What temps were you able to achieve in your oven?
On the tape issue: we've found that the brand of tape makes a huge difference. The better brands (3m, duck) seem to hold together better, while cheap 'office depot' specials, fall apart into a million annoying pieces. With the heated press, I've been skipping the tape since the heat melts its. Instead I've been laying parchment paper (available in the baking section of a grocery store) on the mold before lay-up. Also, a little PAM cooking spray helps with the clean up of any extra epoxy. I have to give credit for that great tip to Dan from Graf snowboards.
G-man,
great info about UHMW. Care to write a short article about material prep? What's the best way to flame treat and what should I be looking for? I've been using a Mapp torch and looking for a slight discoloration and small 'bubbling'. Not sure if this is right or not and it also doesn't work well on thin material. Do you know what industry uses to clean material prior to bonding?
thanks
-kelvin
Check the link below for more info about some 3M stuff to bond low surface energy plastics like UHMWPE, ABS etc.
http://www.epoxy-adhesive.com/adhesives ... Yellow.pdf
http://www.epoxy-adhesive.com/adhesives ... Yellow.pdf
We manually cycled the switch, off at 190*F back on at 170*F. Once we forgot & the temp hit 205*. Heating from the outside like we did creates the problem of not knowing what the temp is inside the mold. We found that the running length of the ski heated quickly, but it took quite a bit longer to get the thicker tip & tail blocks up to temperature.kelvin wrote:Hose-man,
Really nice work! The skis and video look great. What temps were you able to achieve in your oven? <snip>
Hey Kelvin,
Sure, I'd be glad to share some info regarding surface treatment of UHMW. I've been doing a lot of ski building this past couple of months and a lot of on snow testing (while the spring corn is still so good)... not much sleep, but tons of fun. The homebuilt skis continue to amaze me and anyone else who tries them. I've been doing some pretty extensive testing of surface treatment methods, and, somewhat surprisingly, to get a good dyne level for sound bounding of UHMW, the surface treatment parameters are really quite critical.
It seems that just about everyone who sees my skis, or skis on them, wants to buy a pair. I don't really know if I want to go in the direction of building skis as a business (don't want to ruin the fun I'm now having), but, if I ever did sell a pair, I'd want to be pretty sure that they were going to stay together. So, I'm trying to learn as much as possible about bonding UHMW. My first pair, with UHMW sidwalls, have between 30 and 40 long backcountry days on them, and they show no signs of delamination or any other structural problems.
As many of this forum's readers already know, the cap construction method that most of the industry uses for ski building, eliminates the sidewall problems associated with sandwich construction. But, what a lot of skiers don't realize is that a cap constructed ski just can't give the same round flex that a sandwich ski can give. When weighted, the cap construction at the waist of the capped ski is just too rigid to flex into a nice circular arc that is consistent with the arc of the tip and tail of the ski. The resulting turn is a comprimise between where the tip is trying to go, where the waist of the ski is trying to go, and where the tail is trying to go... all different destinations. I never really thought about this until I experienced the first turns on my homemade skis, and then tried to figure out why they skied so much better than anything else than I'd ever been on (remember, too, that I'm the guy building skis with pine cores). They have a very circular flex, no matter how much they are weighted (the binding, however, must be mounted at the correct spot). I'll post more on this topic later, but my point at present is that, if I have a choice, I'll probably never ski on a cap constructed ski again. But, there is a downside to sandwich construction, and that is durability, mostly related to delamination, and that, mostly related to UHMW.
So, Kelvin, after the remaining snow is too beat up to be skiable (hopefully still a few weeks away), I'll submit an article about stuff I've learned about the surface treatment of UHMW... and pictures of skis and presses and other things. Until then, I'll be burning the midnight oil buliding skis, driving to the snow at sunrise, and getting in as many runs as I can before the mid-day sun softens the snow and makes it too grabby.
By the way, in case anyone is wondering, I had my nose to the grindstone for a number of years while my wife worked her way through school and established a career. Now, I'm taking two or three years off work to just play my butt off. It was perfect timing that I discovered skibuilders.com at a time when I could devote a boatload of time to ski building and 'product testing'. Please don't hate me... I'll share much of what I've learned... when the snow is gone.
G-man
Sure, I'd be glad to share some info regarding surface treatment of UHMW. I've been doing a lot of ski building this past couple of months and a lot of on snow testing (while the spring corn is still so good)... not much sleep, but tons of fun. The homebuilt skis continue to amaze me and anyone else who tries them. I've been doing some pretty extensive testing of surface treatment methods, and, somewhat surprisingly, to get a good dyne level for sound bounding of UHMW, the surface treatment parameters are really quite critical.
It seems that just about everyone who sees my skis, or skis on them, wants to buy a pair. I don't really know if I want to go in the direction of building skis as a business (don't want to ruin the fun I'm now having), but, if I ever did sell a pair, I'd want to be pretty sure that they were going to stay together. So, I'm trying to learn as much as possible about bonding UHMW. My first pair, with UHMW sidwalls, have between 30 and 40 long backcountry days on them, and they show no signs of delamination or any other structural problems.
As many of this forum's readers already know, the cap construction method that most of the industry uses for ski building, eliminates the sidewall problems associated with sandwich construction. But, what a lot of skiers don't realize is that a cap constructed ski just can't give the same round flex that a sandwich ski can give. When weighted, the cap construction at the waist of the capped ski is just too rigid to flex into a nice circular arc that is consistent with the arc of the tip and tail of the ski. The resulting turn is a comprimise between where the tip is trying to go, where the waist of the ski is trying to go, and where the tail is trying to go... all different destinations. I never really thought about this until I experienced the first turns on my homemade skis, and then tried to figure out why they skied so much better than anything else than I'd ever been on (remember, too, that I'm the guy building skis with pine cores). They have a very circular flex, no matter how much they are weighted (the binding, however, must be mounted at the correct spot). I'll post more on this topic later, but my point at present is that, if I have a choice, I'll probably never ski on a cap constructed ski again. But, there is a downside to sandwich construction, and that is durability, mostly related to delamination, and that, mostly related to UHMW.
So, Kelvin, after the remaining snow is too beat up to be skiable (hopefully still a few weeks away), I'll submit an article about stuff I've learned about the surface treatment of UHMW... and pictures of skis and presses and other things. Until then, I'll be burning the midnight oil buliding skis, driving to the snow at sunrise, and getting in as many runs as I can before the mid-day sun softens the snow and makes it too grabby.
By the way, in case anyone is wondering, I had my nose to the grindstone for a number of years while my wife worked her way through school and established a career. Now, I'm taking two or three years off work to just play my butt off. It was perfect timing that I discovered skibuilders.com at a time when I could devote a boatload of time to ski building and 'product testing'. Please don't hate me... I'll share much of what I've learned... when the snow is gone.
G-man
Kelvin,
Check my latest post in the 'materials' section. It's not really an 'article' as such, but it is probably even better because it lists the most significant sources of information that I have found regarding flame treatment of UHMW... better to get it straight from the horses mouth rather than... whatever. I hope it is helpful. I think that getting down this flame treatment process is going to be one of the most challenging parts of ski building... adding to the challenge... and the fun, eh.
G-man
Check my latest post in the 'materials' section. It's not really an 'article' as such, but it is probably even better because it lists the most significant sources of information that I have found regarding flame treatment of UHMW... better to get it straight from the horses mouth rather than... whatever. I hope it is helpful. I think that getting down this flame treatment process is going to be one of the most challenging parts of ski building... adding to the challenge... and the fun, eh.
G-man