Fiberglassing fins: which epoxy?

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TWRackers

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With luck I'll finally get to do my first fiberglassing this evening, doing the fins on my Level 3 rocket. I've got sufficient 1½ oz fiberglass cloth for three stepped layers, but I need to know which epoxies can be used. I know West Systems is often used, but I also have some 20 minute finish-cure epoxy; I don't have West Systems on hand. Has anyone successfully used the finish-cure stuff, or does anyone know for sure that it will NOT work?

If you have any info along these lines, please respond soon. I'll be away from my computer for a couple of hours, so hopefully I'll have a few responses by the time I get back.

Oh, the fins are ¼" thick birch plywood and the airframe is Giant Leap's Dyna-Wind tubing.
 

troj

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I would recommend against the Finish Cure epoxy. Any epoxy that's a 1:1 ratio has fillers in it to get the mix ratio, and is not as good of a product.

I've used West Systems, and it will work fine for your application, but my preference is for Fiberglast System 2000.

-Kevin
 

TWRackers

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I would recommend against the Finish Cure epoxy. Any epoxy that's a 1:1 ratio has fillers in it to get the mix ratio, and is not as good of a product.

I've used West Systems, and it will work fine for your application, but my preference is for Fiberglast System 2000.

-Kevin
I can get some West Systems, but I've never heard of (and don't know where to find this evening) the Fiberglast stuff.
 

troj

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I can get some West Systems, but I've never heard of (and don't know where to find this evening) the Fiberglast stuff.
Well, it'd be easier, if I would spell the name correctly.... :rolleyes:

https://www.fibreglast.com/

If you have a local source for West Systems, go ahead and use that. It will work fine.

Part of what I like about System 2000 epoxy is that it has one of the highest Tg (glass transition temperature) values, when properly heat cured. We've built enough large projects with it that we've gone through upwards of 20 gallons of resin.

-Kevin
 

TWRackers

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Well, it'd be easier, if I would spell the name correctly.... :rolleyes:

https://www.fibreglast.com/

If you have a local source for West Systems, go ahead and use that. It will work fine.

Part of what I like about System 2000 epoxy is that it has one of the highest Tg (glass transition temperature) values, when properly heat cured. We've built enough large projects with it that we've gone through upwards of 20 gallons of resin.

-Kevin
Yeah, I can get my hands on some West 105/205 almost immediately, and I really need to get this operation done this weekend, i.e. tomorrow (Saturday). Right now I'm making patterns to cut the cloth, and I'll tackle the layup process in the morning. My L3 rocket may not be painted before Red Glare VI, but it'll be flyable (I think).
 

troj

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Yeah, I can get my hands on some West 105/205 almost immediately
Sounds like that's accomplished via supporting a local business, which is always a good thing!

-Kevin
 

ben_ullman

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I use West System for everything with 205/206 hardeners depending on the application. I used to use US Composites but it was WAY to thin and took forever to thicken using silicia or other additivies. I just never had good luck with it. I would use West for all epoxy applications. We are 1/2 through a gallon now and we might just get a 5 gallon bucket of resin since we use so much.

Ben
 

ben_ullman

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P.S. If you get in a bind you can drive down here (45-60min away) and we have a whole setup and should be able to get one side down every 2-3 hours.

Ben
 

TWRackers

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P.S. If you get in a bind you can drive down here (45-60min away) and we have a whole setup and should be able to get one side down every 2-3 hours.

Ben
Boy, I wish I had seen this a couple of hours ago. I'm leaving you a PM.
 

kandsrockets

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+1.

https://www.uscomposites.com/epoxy.html I've used these resins with great success (and it's at a great price too).

Yup another vote for US Composites. I have used 9 gallons of the 635 in the last 3 months and have nothing but great results with it. I have both med and fast hardners.

Ben if you think this stuff is thinner than west system then you maybe mixing it wrong because this is defently thicker than west system.
 

ben_ullman

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I used the pumps and it was thin. Oh well, I am using West and I am happy :) To each his own

Ben
 

TWRackers

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Well, just finished putting on the last layers of glass on my rocket. :cool: Now to let them cure overnight and check the results. I did one section early this afternoon (the side with the rail buttons) and it looked reasonably good when I pulled the peel ply off. Tomorrow the other three peel plys (plies :confused:) come off and I can evaluate how much sanding or touch-up will be needed. West Systems 105/205 worked pretty well for me. It's those cheapo bagged pieces of fiberglass cloth from the local hobby shop I'm not real happy with. It's like packages of meat from the grocery store: the best sides were to the outside of the packages. :rolleyes:

(For some reason I'm in a :p mood this evening. Probably sleep deprivation.)

[ Hey Ben, I see you're online too. Thanks for the tips this evening. ]
 

ben_ullman

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Good luck!! Plenty of bondo and sandpaper will make anything go away ;)

Ben
 

rrobe99999

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Hey Tom,
This is Russ from SEARS. I'm doing my 1st external fiberglass lamination over wood fins. I used the Home Depot cloth with West System epoxy. What do you guys use to fill the weave?
 
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