vacume bag's and Fiber glassing

This past weekend I went up to a buddy's house and he showed me a technique that he started using for fiberglassing. It involes a food saver vacume bagging machine. He demonstrated it on my air frame for my scratch built 4" V-2 Blossom #47. We started by putting a coating of epoxy resin on the tube, then a layer of 4 oz. fiberglass, followed by a layer of 2 oz. fiberglass. After that came a syntic screen materail followed by a batting. Then the whole thing put into a foodsaver bag, with one end sealed. Next put the open end into the foodsave and the vacuming begins. when the machine is completed it seals the end and you have a body tube that looks like shrink wraped sausage ( funny look'n at first site.) The next day I took it apart and I was very impressed. All the extra epoxy was pressed out into the batting material and it just pealed right off the body tube. This process is top notch, because you get the glass on the rocket for the strenght.. and use a minimal amount of epoxy whitch saves on the weight.

Very cool idea. I just saw an infomercial last weekend about the "Food Saver". Your friend didn't get the idea from the "Chicken Rub", did he? Seriously, this sounds like a great idea. I'd like to hear if anyone else has ever tried this and what their results have been.

Mark

I gotta ask. Usually when you vaccum bag something there are creases and wrinkles. Even though they are fairly flat, they are still slits. How did that affect your finish. Did the wrinkles create "hills and valleys" in the finish? Or am I just deeply confused?

Oh, and one other thing: How was the cleanup of the bags? Were they a mess or perfect?

I expect that the answer to this question will be that the batting solved the problem.

For more information on vacuum bagging with the Tilia FoodSaver (or similar vacuum storage systems), see the article on my web site:Kitchen Table Vacuum Bagging.

(This is a reply to PGerringer's post, but it doesn't look like I can reply to a single post, only to an entire thread.)

You can bag tubes without wrinkles. The main trick is to stretch the reinforcement cloth very tight when applying and to only do a single reinforcement layer at a time. I generally only get slight wrinkles where the excess bag forms a seam at opposite sides.

Also, I've found that using two bags can remove those side seams. Put the part into the inner bag flush against one side seam and pull tight. Keeping the other seam tight, fold the excess over and tape several places across where the seam overlaps. Don't seal this inner bag. Put the whole thing into the outer bag and seal as normal. What I think happens is that since the seams don't overlap in the two bags, there is more equal force around the entire tube.

Originally posted by John Coker
(This is a reply to PGerringer's post, but it doesn't look like I can reply to a single post, only to an entire thread.)

You can bag tubes without wrinkles. The main trick is to stretch the reinforcement cloth very tight when applying and to only do a single reinforcement layer at a time. I generally only get slight wrinkles where the excess bag forms a seam at opposite sides.

Also, I've found that using two bags can remove those side seams. Put the part into the inner bag flush against one side seam and pull tight. Keeping the other seam tight, fold the excess over and tape several places across where the seam overlaps. Don't seal this inner bag. Put the whole thing into the outer bag and seal as normal. What I think happens is that since the seams don't overlap in the two bags, there is more equal force around the entire tube.

Click to expand...

Just a forum hint here. By pressing the "quote" button on the post of the individual you want to address you get the effect that you see here. This let's members know you are referencing that particular post. I did this by pressing the quote button under John's post.

This is the exact method that Roger showed me, I did have one slight wrinkle in the tube, but was easly sanded out. This method worked great. Thanks for the LInk John.

Oh ya to answer the question of the remains of the vacume bag.. it was totally clean. The batten matterial absorbed the excess epoxy. I believe Roger said that it was usable for several times.