Tangible Benefits from Glassing Phenolic Tubes?

[jmmome]

The other option I'm looking at for my two 6" dia. Mercury Redstone & Honest John projects, for which I already have the custom nosecones & the fins, is to fiberglass phenolic tubing, as opposed to waiting for Blue Tube to restock.

From using phenolic about ten years ago, I know it can be brittle & unforgiving for hard landings. Both rockets I'm building will weigh around 18 to 20 pounds.

The other issue I recall is that the phenolic piston I used for main chute deployment seemed to swell over time, and was too tight to freely move in the body tube. Sanding the layers of paper down on the piston was a pain.

I'd love to hear your thoughts as to benefits of glassing the phenolic body tubes. Will the glassing make the tube more forgiving during a harder landing? I'd also love to hear any techniques you may use to prevent the swelling of the piston. Thanks!

 

[David Schwantz]

Hi Mike, I have not used phenolic tube, but I can tell you about glassing tubes. Yes, it will be much more durable, less prone to dings and dents. The glass will also help to transfer the landing force throughout the entire tube. I think that finishing a glass surface is a lot easier than most others. I have used a piston setup before, and the fit and finish needs to be perfect. Also needs to be kept clean, BP residue will cause it to stick. Clean after every flight. And damn you , I just started printing a 5.5" Mercury capsule last night, now I gotta stop and make it bigger

 

[jimzcatz]

Phenolic is as brittle as glass. Not fiberglass but window glass. You don't want to use it unless you are going to wrap it in fiberglass or carbon fiber. No matter what ANYONE tells you, if you dont it WILL eventually crack. in my opinion it's garbage and not worth the time, I would just bite the bullet and get glass tubes.

 

[Steve Shannon]

Look into the Giant Leap flexible phenolic. It’s not brittle like the PML Phenolic and they even sell it with fiberglass already applied. It should be size compatible with the parts you have but I would double check that.

 

[jmmome]

Hi Mike, I have not used phenolic tube, but I can tell you about glassing tubes. Yes, it will be much more durable, less prone to dings and dents. The glass will also help to transfer the landing force throughout the entire tube. I think that finishing a glass surface is a lot easier than most others. I have used a piston setup before, and the fit and finish needs to be perfect. Also needs to be kept clean, BP residue will cause it to stick. Clean after every flight. And damn you , I just started printing a 5.5" Mercury capsule last night, now I gotta stop and make it bigger

Way back in 2012 (I think), Randy Emja, then the owner of Always ready Rocketry in FL, tried to convince me to go with 5.5" for my L3. I insisted on 6" for no apparent reason except it was bigger (Tim "Toolman" Taylor Syndrome). I've stuck with 6" ever since for my historic rocket builds. I ALMOST enjoy building the historic rockets as much as i enjoy flying them. Thanks for the tips, btw!

 

[jmmome]

Look into the Giant Leap flexible phenolic. It’s not brittle like the PML Phenolic and they even sell it with fiberglass already applied. It should be size compatible with the parts you have but I would double check that.

Sadly, their flexible phenolic doesn't come in 6" dia.- only up to 3.9". But I will look into their (K)frame tubing.

But the cheap guy inside me will probably just glass the PML phenolic tubes. Glassing the weird-shaped Honest John 38" long nosecone gave me confidence to try body tubes.

 

[JimJarvis50]

The PML phenolic will break quickly if you don't glass it. However, I have a couple of rockets with that tubing that I glassed with 2 wraps of 6 oz glass. Those tubes are very durable and have lasted for years and dozens of flights. Those same rockets have the PML pistons, but I have not noticed them swelling. I do line the inside of them with something (glass or Kevlar) so that they don't get damaged.

Jim

 

[jmmome]

Phenolic is as brittle as glass. Not fiberglass but window glass. You don't want to use it unless you are going to wrap it in fiberglass or carbon fiber. No matter what ANYONE tells you, if you dont it WILL eventually crack. in my opinion it's garbage and not worth the time, I would just bite the bullet and get glass tubes.

Since I seldom get to fly my rockets here in OH because I'm still a FL weather wimp at heart and don't venture out over the winter months, I'll probably try to glass phenolic tubes for one of the two rockets in queue. Then, I'll TRY to wait patiently until Blue Tube is back in stock.

 

[BDB]

Is 2 wraps to 6 oz the prescribed method? I was thinking of trying a CF sock form Soller Composites. Would a single layer of CF suffice for a L3-type project?

 

[Jee3300R]

Sadly, their flexible phenolic doesn't come in 6" dia.- only up to 3.9". But I will look into their (K)frame tubing.

But the cheap guy inside me will probably just glass the PML phenolic tubes. Glassing the weird-shaped Honest John 38" long nosecone gave me confidence to try body tubes.

I think Loc has 5.5” and 3” flexible phenolic. In any case, flexible or not, I’d glass them.
I actually prefer glassed phenolic to blue tube.

 

[Jee3300R]

Is 2 wraps to 6 oz the prescribed method? I was thinking of trying a CF sock form Soller Composites. Would a single layer of CF suffice for a L3-type project?

Probably, although it would depend on size and motor. My hyperloc 1600 has one layer and has flown on M’s.

I would use glass because it’s less brittle, but the CF looks much nicer with some sanding and a clear coat.

 

[David Schwantz]

I did not have good luck with the blue tube. Swelled up to the point of cracking the 3D printed shells.

 

[Nytrunner]

I did not have good luck with the blue tube. Swelled up to the point of cracking the 3D printed shells.

Did you seal the tube?

 

[HHaase]

How does the Mac Performance phenolic stack up to the other brands? I've really been eyeballing their VTS-6 kit, but man I get the heebie jeebies thinking about having to glass that kit, as somebody that's never done it before.

-Hans

 

[David Schwantz]

Did you seal the tube?

Nope. I did not. Guess maybe I should have. Still flies, just a few cracks in the prints. It is very strong, and heavy.

 

[Jee3300R]

How does the Mac Performance phenolic stack up to the other brands? I've really been eyeballing their VTS-6 kit, but man I get the heebie jeebies thinking about having to glass that kit, as somebody that's never done it before.

-Hans

It is much stronger and more flexible. Lighter than 0.063" wall G12 by maybe a third. I've flown 4" canvas phenolic well past mach.

Definitely do not need to glass the mac performance kits, no spirals to fill, and the parts fit great. Highly recommend.

 

[jmmome]

The PML phenolic will break quickly if you don't glass it. However, I have a couple of rockets with that tubing that I glassed with 2 wraps of 6 oz glass. Those tubes are very durable and have lasted for years and dozens of flights. Those same rockets have the PML pistons, but I have not noticed them swelling. I do line the inside of them with something (glass or Kevlar) so that they don't get damaged.

Jim

Never thought of glassing the inside of the piston- thanks! The Forum has a wealth of experience!!!!

 

[UhClem]

Is 2 wraps to 6 oz the prescribed method? I was thinking of trying a CF sock form Soller Composites. Would a single layer of CF suffice for a L3-type project?

I used a single 6oz. layer of fiberglass.

I still have my ca. 1996 PML Quasar that I used for my L1 but it isn't what it used to be. The tube (not glassed) suffered zippers and other such problems until I refitted it into an anit-zipper configuration.

 

[SDramstad]

2 wraps would be good. A single sock wouldnt give much strength but 2 layers would. Let the first sock set up until its not sticky and then apply a second one on top of it.

 

[curtisheisey]

I'm a big fan of glassing.

If you take the route of glassing, the glassed material will provide most of the support, so why not just use a cardboard tube?

Also, look at carbon fiber sock material from soller composite.

When you use the sock, you want to get a size of larger diameter than the tube, so that you can stretch it out. This provides greater strength.

 

[jmmome]

I'm a big fan of glassing.

If you take the route of glassing, the glassed material will provide most of the support, so why not just use a cardboard tube?

Also, look at carbon fiber sock material from soller composite.

When you use the sock, you want to get a size of larger diameter than the tube, so that you can stretch it out. This provides greater strength.

I'd use a cardboard tube if I could find a 6" one. Are they made? I didn't see them at my usual sources.

 

[curtisheisey]

I'd use a cardboard tube if I could find a 6" one. Are they made? I didn't see them at my usual sources.

Ahh. Yes, a problem. And with a non-standard cardboard tube, then you have an issue with the NC and couplers.

 

[thzero]

Ahh. Yes, a problem. And with a non-standard cardboard tube, then you have an issue with the NC and couplers.

Roll your own?

 

[SDramstad]

I rolled my own for my level 3, 6 inch diameter rocket. Used 6 inch coupler blue tube wrapped with Mylar for a mandrel. It's not that hard to do

 

[heada]

I had a 7.5" PML tube that was glassed come in flat (electronics never fired either apogee or main) from ~3000 ft to land on grass and the only thing I had to fix was the fillets on the fins. PML phenolic that has been glassed is very stout. Seems like the wider the tube, the more forgiving the phenolic is. I've had the lip of tubes chip and the fix for that was wicking in thin CA, just like cardboard.

 

[mtnmanak]

On PML phenolic, I have used a layer of CF for strength (not a CF sock, actual composite fabric) and then a layer of FG over that for aesthetics (for that, a sock is great). CF then FG seems to work well, never had an issue with rocket, even in cold weather.

For the pistons, I have just spread a nice layer of epoxy on the inside of them and that has worked well.

 

[BDB]

I rolled my own for my level 3, 6 inch diameter rocket. Used 6 inch coupler blue tube wrapped with Mylar for a mandrel. It's not that hard to do

Interesting idea. How many layers did it take to make a tube sturdy enough for an M motor?

 

[jd2cylman]

I rolled my own for my level 3, 6 inch diameter rocket. Used 6 inch coupler blue tube wrapped with Mylar for a mandrel. It's not that hard to do

And it was a beautiful thing...

 

[kalsow]

Interesting idea. How many layers did it take to make a tube sturdy enough for an M motor?

https://www.rocketryforum.com/threads/keep-it-simple-stupid-my-level-3-build.159108/post-1992319
His first post said 7 1/2 feet of cloth wrapped on a 6 inch tube. So that's 5 wraps. I can't be sure, but it looks like 6 oz carbon fiber.

 

[SDramstad]

https://www.rocketryforum.com/threads/keep-it-simple-stupid-my-level-3-build.159108/post-1992319
His first post said 7 1/2 feet of cloth wrapped on a 6 inch tube. So that's 5 wraps. I can't be sure, but it looks like 6 oz carbon fiber.

Good eye! Thats exactly right. And 5 layers was overkill. 3 would probably do it for small M's but would have to roll one to know for sure.