Alright, I know this topic has been discussed ad ad nauseum, but it is difficult to find relevant (not to mention current) information using the search feature. Please put all your current info here.
What brands and formulations of epoxy is everyone using? I know West Systems is a favorite, as well as QCM. I also know of Jeffco, Aeropoxy, Raka, and a few others. What is a good "budget" epoxy that has a low cure temp? Any horrible experiences, brands that should be banished from ski building forever?
Favorite Epoxies
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
Another question that I have is how much epoxy is used? I have a fair bit of experience using fiberglass and resin (three 15' canoes, 4 gallons of resin each).
I was thinking the one gallon west systems kit, but I've heard that if mixed correctly, you run out of hardener. Anyways, if I could get a smaller kit, I could afford the resin (or even get a few sample packs) sooner.
I was thinking the one gallon west systems kit, but I've heard that if mixed correctly, you run out of hardener. Anyways, if I could get a smaller kit, I could afford the resin (or even get a few sample packs) sooner.
Regarding the amount of resine to use, I already asked my epoxy provider, and he answered to use the same weight of resine than the weight of fiberglass plus 10% for waste of left over.
This means for a single ski roughly 2 times 2 meter x 15cm of .710 kg per square meter fiberglass, some thing like half a kilogram per ski.
Just a idea not yet verified. Any other figure?
This means for a single ski roughly 2 times 2 meter x 15cm of .710 kg per square meter fiberglass, some thing like half a kilogram per ski.
Just a idea not yet verified. Any other figure?
Here’s my $0.2
I use Resin Research ( www.resinresearch.net ) epoxies at the moment. And have used Raka , West systems, and System 3 in the past. They have all worked great for me, but I’m finding the wet out with the RR epoxy is easier than most and they are almost water clear. I have had quite a bit of variation in color with the other brands. And so far they show the best UV stability of any epoxy I have used. There was very little yellowing in the sun as evidenced by my surfboards during the trip to Socal last year.
The RR epoxies have 4 modulus of stiffness that you can mix and match and a very fast and very slow hardeners that can also be mixed. Last time I bought a 3 gallon kit from them it was $180.00 included shipping.
I have a break down of how I apply epoxy here. http://www.skibuilders.com/phpBB2/viewt ... highlight=
Scroll down it’s towards the bottom.
I came out to ~4 lb of epoxy per pair of skis. That’s ~$26.00 per pair. Smaller kits will cost a bit more per unit of volume.
They have finally updated their site! Lots of new data about there products. Looks like the prices have gone up a bit $192 for the 3 gallon kit today. The 3 pint kit will do at least one air of skis and is $38. Looks like they have also added a very slow hardener. Really nice for working in the heat of summer. A new pro system for infusion applications and high temp post cures. See here http://resinresearch.net/_wsn/page9.html I’m excited about this looks like a good product for skis.
Hafte
I use Resin Research ( www.resinresearch.net ) epoxies at the moment. And have used Raka , West systems, and System 3 in the past. They have all worked great for me, but I’m finding the wet out with the RR epoxy is easier than most and they are almost water clear. I have had quite a bit of variation in color with the other brands. And so far they show the best UV stability of any epoxy I have used. There was very little yellowing in the sun as evidenced by my surfboards during the trip to Socal last year.
The RR epoxies have 4 modulus of stiffness that you can mix and match and a very fast and very slow hardeners that can also be mixed. Last time I bought a 3 gallon kit from them it was $180.00 included shipping.
I have a break down of how I apply epoxy here. http://www.skibuilders.com/phpBB2/viewt ... highlight=
Scroll down it’s towards the bottom.
I came out to ~4 lb of epoxy per pair of skis. That’s ~$26.00 per pair. Smaller kits will cost a bit more per unit of volume.
They have finally updated their site! Lots of new data about there products. Looks like the prices have gone up a bit $192 for the 3 gallon kit today. The 3 pint kit will do at least one air of skis and is $38. Looks like they have also added a very slow hardener. Really nice for working in the heat of summer. A new pro system for infusion applications and high temp post cures. See here http://resinresearch.net/_wsn/page9.html I’m excited about this looks like a good product for skis.
Hafte
Yes the product 21 system is what I have been using. It was all they offered on the site... until recently. The new composite pro system 3:1 mix looks interesting. I like what they have to say about it and may give it a try when my current batch is gone.
I think the 2020 resin with the fast hardener is what I have right now. I have used the 2000 and the 2040 on other projects. I'm not an engineer so most of what I do is trial and error. I was thinking with the skis that the medium flex would help keep things together better.
The additives also have me thinking about my clear coats and speeding them up too.
I think the 2020 resin with the fast hardener is what I have right now. I have used the 2000 and the 2040 on other projects. I'm not an engineer so most of what I do is trial and error. I was thinking with the skis that the medium flex would help keep things together better.
The additives also have me thinking about my clear coats and speeding them up too.
I've used System Three before on past projects, such as gluing ash gunwales to fiberglass hulls. I liked it.
I've used west systems a bit in the past too, pretty much the cream of the crop and foolproof, but $$$.
My old employer uses Jeffco to make their carbon fiber rudders, with very good results from what I have observed. I think they even switched from west systems to jeffco for gluring up teak toerails for the boats. I'm not sure if this was due to volume pricing or increased UV resistance, but the mix they use DOES NOT cure clear.
Anyone use the MAS epoxy?
When I came across this on ebay, I knew I had heard of it before, IIRC it is supposed to be comparable to west systems.
EDIT: Jamestown Distributors (marine/epoxy/glass supplier for a lot of small boatbuilders) has 1/2 gallon MAS and a quart of hardener for $64.78. The guy on ebay is selling what apperas to just be hardener for $53.99.
I've used west systems a bit in the past too, pretty much the cream of the crop and foolproof, but $$$.
My old employer uses Jeffco to make their carbon fiber rudders, with very good results from what I have observed. I think they even switched from west systems to jeffco for gluring up teak toerails for the boats. I'm not sure if this was due to volume pricing or increased UV resistance, but the mix they use DOES NOT cure clear.
Anyone use the MAS epoxy?
When I came across this on ebay, I knew I had heard of it before, IIRC it is supposed to be comparable to west systems.
EDIT: Jamestown Distributors (marine/epoxy/glass supplier for a lot of small boatbuilders) has 1/2 gallon MAS and a quart of hardener for $64.78. The guy on ebay is selling what apperas to just be hardener for $53.99.
I'm thinking about using U.S. Composites brand, $60 for 1.5 gallons!
Reading up on it, it sounds a lot like the raka epoxies.
here is a quick discussion about the epoxy:
http://www.kayakforum.com/cgi-bin/Build ... ead/103140
Reading up on it, it sounds a lot like the raka epoxies.
here is a quick discussion about the epoxy:
http://www.kayakforum.com/cgi-bin/Build ... ead/103140
I ended up going with Mr. Fiberglass epoxy.
I was initially apprehensive about this brand, but Dave Muesing, the owner, is extremely helpful.
He responds to e-mails within a day, where I have yet to hear from many of the other companies period. Roy from QCM did get back to me quickly, but was somewhat unpleasant in response to my question about the heat cure.
Dave immediately sent me the manufacturers name (Reichhold) and the model numbers of his epoxy:
"The Resin is: 37-127
The Slow Hardener is: 37606-00
The Fast Hardener is: 37614-00
The Med Hardener is a combination of Slow & Fast"
With this I was able to look up the technical specs. Here is the data for the resin (different hardener though):
Tensile Strength, psi
9 – 10.000
Tensile Elongation, Percent
2.2 – 2.5
Flexural Strength, psi
17 – 19.000
Flexural Modulus, psi x 10-5
4.5 – 5.0
From what I have seen of other brands, these specs are essentially the same.
I was initially apprehensive about this brand, but Dave Muesing, the owner, is extremely helpful.
He responds to e-mails within a day, where I have yet to hear from many of the other companies period. Roy from QCM did get back to me quickly, but was somewhat unpleasant in response to my question about the heat cure.
Dave immediately sent me the manufacturers name (Reichhold) and the model numbers of his epoxy:
"The Resin is: 37-127
The Slow Hardener is: 37606-00
The Fast Hardener is: 37614-00
The Med Hardener is a combination of Slow & Fast"
With this I was able to look up the technical specs. Here is the data for the resin (different hardener though):
Tensile Strength, psi
9 – 10.000
Tensile Elongation, Percent
2.2 – 2.5
Flexural Strength, psi
17 – 19.000
Flexural Modulus, psi x 10-5
4.5 – 5.0
From what I have seen of other brands, these specs are essentially the same.
QCM
Pressed our first pair of phat powder skis today. We chose QCM epoxy after reading the interview with Roy W. posted on the Ski Builders web site. Dealing with Josh E. at QCM was a pleasure and he really encouraged this project and offered many useful bits of info.
We bought EMV-0043 epoxy and ECA-032 curing agent for our first experience. The resin is rather thick at about 8000cps viscosity. We scooped it into mixing cups with a 4oz. measuring scoop. Five such cups were lined up ready for a 1 oz. full-stroke of the dispensing pump we used to meter-in the watery curing agent during the lay up. The epoxy mixes easily and becomes very workable. The pot life is rated at 25 minutes which was just enough time for our first ski build.
We pressed it at 35 psi in the bladder. We ran the temperature at 120F for the first hour during the “cure” then bumped it up to 170F for a post cure bake of nine more hours. This post cure heat cycle is where the molecules cross-link and the bond becomes durable. After the heat cycle the press cools to ambient temperature and sits over night under air pressure.
We attached a beaded wire thermocouple with Kapton tape directly to the aluminum surface on the heated lower press form and use this for input to our temperature controller. The imbedded TC within our silicone heater blanket cannot be used for accurate hot plate control above 150F. Another TC is taped to the top sheet of the ski right in the middle so we can measure the hear transfer through the ski. It stabilizes at about 145F on the top surface of the ski inside the pneumatic press. I’m sure that the thinner parts of the ski are much more evenly heated top to bottom.
The skis exhibit absolutely zero spring back! Actually we guessed that about 20% of the curvature would relax and we shaped our press forms accordingly. Now our skis have allot of tip and tail curvature, almost twin-tip looking. Future forms will have a better shape.
Our powder ski design is 184 cm long with 137-107-127mm (tip, waist, tail). The side cut radius is 28.3m according to the SolidWorks model. The boot center mark is coincident with the waist point on the ski and is 820mm from the tail. The core is 75% poplar and 25% birch. Its 10.7mm thick under foot and tapers to 2.3mm thick at each end. The thin ends are planed parallel and the taper begins at the running length, this makes for nice looking tip and tail profiles.
We started the cores for the next pair of boards. Thinking about increasing their thickness to about 12mm and also adding some unidirectional carbon in the mid sections. We plan to add UHMW-PE sidewalls and tip spacers on the next pair too.
The Resin Research product looks interesting. We may give this a try after we run out of QCM.
-Shif
We bought EMV-0043 epoxy and ECA-032 curing agent for our first experience. The resin is rather thick at about 8000cps viscosity. We scooped it into mixing cups with a 4oz. measuring scoop. Five such cups were lined up ready for a 1 oz. full-stroke of the dispensing pump we used to meter-in the watery curing agent during the lay up. The epoxy mixes easily and becomes very workable. The pot life is rated at 25 minutes which was just enough time for our first ski build.
We pressed it at 35 psi in the bladder. We ran the temperature at 120F for the first hour during the “cure” then bumped it up to 170F for a post cure bake of nine more hours. This post cure heat cycle is where the molecules cross-link and the bond becomes durable. After the heat cycle the press cools to ambient temperature and sits over night under air pressure.
We attached a beaded wire thermocouple with Kapton tape directly to the aluminum surface on the heated lower press form and use this for input to our temperature controller. The imbedded TC within our silicone heater blanket cannot be used for accurate hot plate control above 150F. Another TC is taped to the top sheet of the ski right in the middle so we can measure the hear transfer through the ski. It stabilizes at about 145F on the top surface of the ski inside the pneumatic press. I’m sure that the thinner parts of the ski are much more evenly heated top to bottom.
The skis exhibit absolutely zero spring back! Actually we guessed that about 20% of the curvature would relax and we shaped our press forms accordingly. Now our skis have allot of tip and tail curvature, almost twin-tip looking. Future forms will have a better shape.
Our powder ski design is 184 cm long with 137-107-127mm (tip, waist, tail). The side cut radius is 28.3m according to the SolidWorks model. The boot center mark is coincident with the waist point on the ski and is 820mm from the tail. The core is 75% poplar and 25% birch. Its 10.7mm thick under foot and tapers to 2.3mm thick at each end. The thin ends are planed parallel and the taper begins at the running length, this makes for nice looking tip and tail profiles.
We started the cores for the next pair of boards. Thinking about increasing their thickness to about 12mm and also adding some unidirectional carbon in the mid sections. We plan to add UHMW-PE sidewalls and tip spacers on the next pair too.
The Resin Research product looks interesting. We may give this a try after we run out of QCM.
-Shif
Last edited by SHIF on Fri Jul 27, 2007 11:28 pm, edited 2 times in total.
Well, I got home today from work to find two packages waiting. I figure 1 box for the epoxy, 1 box for the hardener and pumps.
I open up the small box first, I immediately see that it is not Mr. Fiberglass. Uh, ok, back to the invoice. Someone sent me System Three Silvertip Epoxy.
After a minut of looking over the invoices, I realized that Fiberglass Supply out of Bingen, WA sent me a 1.5 Quart sample pack, huge props to them!
I've never seen any epoxy so clear, both components look like water. This ought to be lots of fun to use.
http://www.systemthree.com/p_st_lamresin.asp
Combined with the Mr. Fiberglass epoxy that i purchased at an awesome discount I now have enough to do at least three pairs of skis. Time to order more from the Kam's...
I open up the small box first, I immediately see that it is not Mr. Fiberglass. Uh, ok, back to the invoice. Someone sent me System Three Silvertip Epoxy.
After a minut of looking over the invoices, I realized that Fiberglass Supply out of Bingen, WA sent me a 1.5 Quart sample pack, huge props to them!
I've never seen any epoxy so clear, both components look like water. This ought to be lots of fun to use.
http://www.systemthree.com/p_st_lamresin.asp
Combined with the Mr. Fiberglass epoxy that i purchased at an awesome discount I now have enough to do at least three pairs of skis. Time to order more from the Kam's...