My next project

[gdiscenza]

Pardon my ignorance, but is peel ply a consumable or can it be re-used?

I'm trying to teach myself the art of fiberglassing, and before I start the hardest part (spending money) I'm trying to assemble as much information as possible.

Thanks,

G.D.

[tfish]

GD, I'ts consumable. I guess you could peel off all the dried on epoxy and re-use it. But if you left any one it could make divits in the layup.

Tony

[tfish]

I was able to get some more work done on the rocket. I layed up a new nose cone, cut the fin slots in the body tube and got the fins cut out.


I think it looks pretty good so far. I borrowed a buddies jig to bevel the leading and trailing fin edges.

Tony

[n3tjm]

Nice thread . I think the rocket will look better with the upper tube the length it was in the video

[DAllen]

Easy question...I've fiberglassed cardboard and phenolic tubes before but in rolling your own I see that you weigh the fiberglass needed prior to layup and then weigh the epoxy...Just so I am clear, the weight of the epoxy is 1:1 to the weight of the glass - right? This video has me thinking of doing a project over the summer involving rolling all of my own tubes but I need to calculate the cost so I can get an idea of what I am getting into.

This is what I am considering...7 tubes each are 25" long and 2.5" diameter and 5 wraps of 6oz cloth brings it to 31.8oz~ of cloth. (I think I did that right - lol)

Also, I see there are other kinds of resin for glassing (polyester?) and I was wondering if anyone reading this knows what the strength difference is between the polyester and the epoxy based resins are?

-Dave

[tfish]

Yes, You want your ratio of epoxy to glass to be about 1-1. I weigh my glass ahead of times..so that I know how much epoxy to make up...as not to waste a bunch.

I'll take a stab at figuring this out..some one can check my math..please!

Lets call the circumfrence of your 2.5" tubes 7.9", times 5 layers, plus a tad extra = 41"

lets go with them being 26" long..for some waste..times 41", times 7 tubes
= 7,462 Sq inches of fiberglass

1 Sq yd = 1296 sq inches

7,462 sq inches devided by 1296 sq inches = 5.76 and that would be sq yds of fiberglass..and we know that each yard weighs 6 ounces..so

5.76 x 6 = 34.56 ounces of epoxy

You'll have to figure out how to fit your 7 - 26" x 41" pieces of fiberglass out of whatever size fiberglass you plan of buying.
You'll also need to find out how much your epoxy weighs per fluid ounce.

[troj]

I'll take a stab at figuring this out..some one can check my math..please!

Math is good, Tony

One thing is that 7 layers of 6oz cloth seems pretty hefty, to me, Dave. Why do you plan on 7 layers?

-Kevin

[nh4clo4]

Math is good, Tony

One thing is that 7 layers of 6oz cloth seems pretty hefty, to me, Dave. Why do you plan on 7 layers?

-Kevin

It's 5 layers, but 7 tubes...

[troj]

It's 5 layers, but 7 tubes...

Doh!

-Kevin

[Rocketman248]

Are all 7 tubes going in one rocket? If so, I'm definitely intrigued!

[DAllen]

Are all 7 tubes going in one rocket? If so, I'm definitely intrigued!

I will probably not build it this way but I was curious...7 25" tubes = 2 stage tube fin.

I think I figured on 6 1/2 tubes or a little less so seven would give me some wiggle room as it were.

Once I stop deliberating one which build method to use I will have a build thread. I have all the electronics already just need to decide how it's all going to go together.

[cwbullet]

Nice so far. i can't wait to see more.

[skyspike1]

Quick question, ever think of layering different weights of cloth for more strength with less mass/weight?? I've never glassed the tubes of my rockets yet, but I've been shaping custom surfboards my whole life,(yeah..it's different) but we never layer same weight twice. Usually,depending on designed use; Big wave gun,shortboard,fish hybrid ect. weather you want a more flexible or rigid s tick...Example: 1 single layer 8 or 10 oz on rocker,(bottom) of board for flex. And 2 layers lighter weight, 1 layer 6oz under 1 layer 4oz on deck,(top) for strength. a layer of 4oz over 1 layer 6oz,(glazed w/polyester resin between) is far stronger than even 16 oz cloth. Surf board shapers, and boat hull builders never glass multiple layers with same weight cloth. Staggering weights is same principle as plywood does for strenght by running opposite grain direction in each ply....Just something to think about! (Surfboards are my no.1 hobby) I'm trying to cross over some of my techniques....both ways. (And I prefer POLYESTER resin always over epoxys...EEEW) Thanx, let me know what u think..

[tfish]

I've given your question some thought and have not come up with many pro's or cons. I could see how it might be stronger. I too think about laying things in relations ship to plywood. Not so much as grain direction but as in number of layers. 3 ply 3/8" ply is not as strong as 7-ply 3/8" plywood. If you were to burn off all the epoxy from a a sheet of G10..you would see about 20 layers of thin fiberglass.
The first stuff I ever glassed, was some little 8 fishing prams (a type of row boat) and was using polyester resin and glass. My first glassed rockets were with a couple of layers of glass and polyester resin. It worked and I have no real reason to using epoxy now, other then one of my co-workers always told me polyester resin is not an adhesive. He use to build surfboards too. Another co-worker, who does some of the 'art work' on my rockets has painted a couple of cool boards.


Tony

[skyspike1]

AWSOME graphic, would like to have seen more of that board...pretty full nose, must be longboard, looks like full nose maybe slight concave underneath, triple-stringer,probably 3/8. Pinched rails around nose, maybe 9'+ range? NICE.

[tfish]

I don't surf. Next time I see him I'll find out the specs on the board and will PM you.

I was able to bevel the fins today. I borrowed my buddies jig to do them.


http://www.youtube.com/watch?v=WSI9--ClSYc

Tony

[tfish]

Fin prep and attatchment using a fin alignment guide.


http://www.youtube.com/watch?v=EwvKR5Lfolk

Tony

[tfish]

I got started on doing the tip to tip fiberglassing of the fins. The method that I use is the 1/3 - 2/3 - Full


http://www.youtube.com/watch?v=PtYYsX3VEmc

I went with all fiberglass. Hopefully to prove that you can do some extreme flights with an all hand layed fiberglass rocket. Hopefully it works out.

Tony

[dixontj93060]

So Tony, the peel ply I use is fabric (like this but the West System brand). It looks like the stuff you use is almost like parchment paper. Is it something different/special?

[tfish]

The stuff I use is from aircraft spruce http://www.aircraftspruce.com/catalo...ges/vb7025.php
The quailites that I like in it is. It's stiffness. It's almost as stiff as a piece of 'white paper' Other Peel ply that I've seen are pretty flimsy. I feel that the stiffness of the peel ply I use, helps to smooth things out.

I think in the making a nose cone video you can see me trying to fold a piece of the peel ply to help get it down to the tip. This is towards the end of the video when I have the mold in the vise. That shows how stiff this stuff is. It still work for tubes and things down to 29mm. In this last video you'll see how I use it for tip to tip lay ups. Make sure you see how I use several pieces of peel ply to do this. I took me awhile of doing the tip to tip with peel ply to get the right method of using peel ply on it down It really eliminates a lot of the sanding.

Below is a photo of the tip to tip down on the video. You can't even see the fiberglass weave. The texture that you can see is from the pours of the peel ply. You are looking at a 2" wide area. The 'ridges' on the sides of the photo are from the first 2 strips of peel ply that I put down. I feel so strongly that thick or stiff peel ply works wonders that I felt a photo might help get the point across.



Tony

[DAllen]

This thread ought to be a sticky.

[Rocketman248]

This thread ought to be a sticky.

Ummm....It already is...

[UPscaler]

Tony,
maybe you could guide me a little. I laminated my big daddy tube with carbon fiber, and I put peel ply on it, when it was dry there was endless amounts of air bubbles, I made sure to wet out the epoxy nicely, and it looked good before the peel ply, I just don't know what to do. I plan on doing something similar to this (except a commercial nosecone, and 38mm min diameter) and don't want the tube to come out looking like crap.



Thanks!

Braden

[tfish]

I'm not really following you. The peel ply goes on as soon as you get done with the layup..while every thing is still wet.

Tony

[Le Aeronautical]

What an awesome set of videos you have tfish!

In the body tube coupler video you mention that you've used gas station fiberglass pipe. Where can you buy that and about what does it cost (any size, maybe 3" dia/foot or something), approximately?

[UPscaler]

I'm not really following you. The peel ply goes on as soon as you get done with the layup..while every thing is still wet.

Tony

Tony,
Right, I wrapped the tube in carbon, while wetting out the cloth just like you did, but I put the peel ply on (not the same kind you use) and after it dried I pulled it off, and there are spots with big dings all over. The cloth is dry where the divots are, was it a matter of air or simply insufficient wetting of the cloth?

[Le Aeronautical]

Tony,
Right, I wrapped the tube in carbon, while wetting out the cloth just like you did, but I put the peel ply on (not the same kind you use) and after it dried I pulled it off, and there are spots with big dings all over. The cloth is dry where the divots are, was it a matter of air or simply insufficient wetting of the cloth?

I have had similar results when working with composites and using peel ply fabric. Even if you use the right proportions of epoxy to fiber the peel ply fabric tends to suck up too much epoxy, especially under vacuum (i.e. vacuum bagging). I suggest using perforated peel ply release film instead which also leaves a smoother finish because the perforations are further apart (1/4", 1/2", etc) and because it's a smooth plastic film. There is also shrink peel ply that you can buy, I've never used it but I've read that it works great for making body tubes.

[redsox15]

how is this project going? really interesting build so far! great videos

Matt

[blackjack2564]

What are the fin dimensions and what size [thick] plate did you start with?

[tfish]

Matt, The electronics bay is done and the rocket is ready for paint. I also started an addition/remodel to my house and have not had much free time. I do plan on flying it in August.

Blackjack, I'll have to look up the fin dimensions when I get home in a couple of days. They are .125' G10.

Tony