aadamson
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I broke down over the weekend and put on my science experiment lab jacket. I have a 3" rocket that I'm building that is my science experiment rocket. It's simply a full length piece of LOC tubing. But I've dual deployed it with a home-made altimeter bay, ejection charge holders and I've experimented with nylons on the outside. I decided I was going to continue the experiment and try my hand and glassing a set of fins. I cut them and sanded to shape and beveled them. As it turns out with plywood, they were slightly warped and as they were made out of 1/8 plywood.
I tried eveything to get them straight, Ironing them helped the most, but still they were slightly bowed. I'd done some research about using the foodsaver to do vacuum bagging and as luck would have it, the local stores (linens and things and bed bath and beyond) carried the 550. I also asked my wife who saves all kinds of coupons and she had a 20% off coupon for Linens and things. Of I went to buy one.
At the same time, I was thinking about keeping weight down during the process and not making the fins much thicker. I stopped at the local hobby store and picked up some 6, 2, and .75 oz fiberglass cloth. Next to the fabric store to get some "backing material" - as it turns out, cotton batting, or poly batting works just fine. Next stop was the local boat supply house to see if I could find some "release film". As luck would have it, they actually had some of the "West Systems" film. (anyone know what this film is really? I'll bet you can buy it at the fabric store if I knew what it was, some sort of poly woven fabric)
Ok, I was set, had everything that I needed.... except. Cutting all those pieces would be a pain with scissors, so another stop at the fabric store (they are starting to know me by name
) to pick up one of those self healing pads and a rotary cutter. They had a package deal where I also got a large clear ruler made for the rotary cutter. (man are these things cool, if you need to cut fabric, just like a hot knife thru butter - but that's another story)
So, I spend an hour cutting all the pieces. I made one little change from the preferred instuctions. Normally, you build a sandwich from an outerlayer of vacuum bag, backing material (this absorbs the excess epoxy), release film, part being bagged, release film, bag. I changed in that I didn't see how the backing material only being on one side, would soak up the excess epoxy on the side that didn't include backing. So I added one on both sides.
First I built a place to work. I layed down a piece of wax paper to make cleanup easy. Next a layer of the backing, then a layer of the release film (I make this be 2x the size I wanted so I could just fold it over). I then laid down a piece of the .75 oz glass and made it as flat as possible.
I then mixed up some slow 206/105 West Systems. Glad I did to as I only got 3 fins done in that batch. Was working slow to make sure I didn't get wrinkles. I painted the epoxy on the plywood fin, all sides and the edges.
Next, I laid the epoxied fin down on the sandwich bed and made sure the lower glass layer stayed straight. If you haven't worked with thin glass and wet epoxy, it's a pain, but be careful and go slow.
I then laid the top piece of glass on and made sure there were no bubbles. Next fold the release film over, lay on a top backing sheet and slide into the foodsaver bag. All this while trying to keep it from sliding or wrinkling. Actually, thats easier than you think as epoxy is tacky and the wood grain actually kept most everything from sliding around.
I got 2 fins in one "large pre made bag" and the third in another bag, if you are careful and don't get the epoxy everywhere, the bags are reusable.
Then I placed the bag in the machine, pushed and held the button and watched all the air get sucked out. This also seals the bag, so you don't have to leave it hooked up to a vacuum pump all night making noise. Wow, too cool, the fin outline was easily seen thru the batting, etc.
Next I laid the fins in the bags on the couter top and put another flat surface on top of them and then all the Phone books I could find. I wanted these suckers to be straight and flat.
And off to bed I went.
This morning, I got up and opened the bags.... Man, this is awesome, they are perfect. I could get hooked on this big time for things like thin CR's, fin laminates, etc. Anything that needs to be laminated, this is a perfect setup.
I'll take pictures on this last fin I have to do as I do it tonight. This method comes highly recommended. Now I'm going to have to try a body tube using the method.
Alan - getting way out of control in my wifes kitchen
I tried eveything to get them straight, Ironing them helped the most, but still they were slightly bowed. I'd done some research about using the foodsaver to do vacuum bagging and as luck would have it, the local stores (linens and things and bed bath and beyond) carried the 550. I also asked my wife who saves all kinds of coupons and she had a 20% off coupon for Linens and things. Of I went to buy one.
At the same time, I was thinking about keeping weight down during the process and not making the fins much thicker. I stopped at the local hobby store and picked up some 6, 2, and .75 oz fiberglass cloth. Next to the fabric store to get some "backing material" - as it turns out, cotton batting, or poly batting works just fine. Next stop was the local boat supply house to see if I could find some "release film". As luck would have it, they actually had some of the "West Systems" film. (anyone know what this film is really? I'll bet you can buy it at the fabric store if I knew what it was, some sort of poly woven fabric)
Ok, I was set, had everything that I needed.... except. Cutting all those pieces would be a pain with scissors, so another stop at the fabric store (they are starting to know me by name
) to pick up one of those self healing pads and a rotary cutter. They had a package deal where I also got a large clear ruler made for the rotary cutter. (man are these things cool, if you need to cut fabric, just like a hot knife thru butter - but that's another story)So, I spend an hour cutting all the pieces. I made one little change from the preferred instuctions. Normally, you build a sandwich from an outerlayer of vacuum bag, backing material (this absorbs the excess epoxy), release film, part being bagged, release film, bag. I changed in that I didn't see how the backing material only being on one side, would soak up the excess epoxy on the side that didn't include backing. So I added one on both sides.
First I built a place to work. I layed down a piece of wax paper to make cleanup easy. Next a layer of the backing, then a layer of the release film (I make this be 2x the size I wanted so I could just fold it over). I then laid down a piece of the .75 oz glass and made it as flat as possible.
I then mixed up some slow 206/105 West Systems. Glad I did to as I only got 3 fins done in that batch. Was working slow to make sure I didn't get wrinkles. I painted the epoxy on the plywood fin, all sides and the edges.
Next, I laid the epoxied fin down on the sandwich bed and made sure the lower glass layer stayed straight. If you haven't worked with thin glass and wet epoxy, it's a pain, but be careful and go slow.
I then laid the top piece of glass on and made sure there were no bubbles. Next fold the release film over, lay on a top backing sheet and slide into the foodsaver bag. All this while trying to keep it from sliding or wrinkling. Actually, thats easier than you think as epoxy is tacky and the wood grain actually kept most everything from sliding around.
I got 2 fins in one "large pre made bag" and the third in another bag, if you are careful and don't get the epoxy everywhere, the bags are reusable.
Then I placed the bag in the machine, pushed and held the button and watched all the air get sucked out. This also seals the bag, so you don't have to leave it hooked up to a vacuum pump all night making noise. Wow, too cool, the fin outline was easily seen thru the batting, etc.
Next I laid the fins in the bags on the couter top and put another flat surface on top of them and then all the Phone books I could find. I wanted these suckers to be straight and flat.
And off to bed I went.
This morning, I got up and opened the bags.... Man, this is awesome, they are perfect. I could get hooked on this big time for things like thin CR's, fin laminates, etc. Anything that needs to be laminated, this is a perfect setup.
I'll take pictures on this last fin I have to do as I do it tonight. This method comes highly recommended. Now I'm going to have to try a body tube using the method.
Alan - getting way out of control in my wifes kitchen
