Question about Phenolic air frames?

[AfterBurners]

https://giantleaprocketry.com/products/components_airframes.aspx#Phenolic_Airframes

I just wanted to know what this material is like to work with? I never worked with it before and is it sturdy or does it crack easily.

What types of adhesives work best with it?

Do most of you hand sand the tube or use a power sander?

I'm considering using Giant Leaps material for my next 4" scratch build. Nose cones, MMT, Air frame, Center Rings etc.

I know they are a well known and reputable vendor.

Thanks!

 

[cavecentral]

Phenolic is brittle, but this is an improved version. It says it is less brittle, but I never tried it.

 

[rstaff3]

I have had good luck with unglassed GL phenolic. Unlike my experience with PML's stuff. It's easy to work with but sand areas that will be bonded. Use epoxy.

 

[cbrarick]

hmmmm what is the speed of phenolic or is that a bad question?
It's heavier then paper and waaay more brittle. I once saw someone spend tons of time making a beautiful phenolic rocket. The thing was absolutely perfectly finished. Totally glass like. First flight, it hits a rock on landing, under chute & that was the end of that. Big chunk broken off with several cracks. Bummer.

 

[tomsteve]

I'm considering using Giant Leaps...hey are out of stock on the 4"(3.9) airframe.

 

[Steve Shannon]

hmmmm what is the speed of phenolic or is that a bad question?
It's heavier then paper and waaay more brittle. I once saw someone spend tons of time making a beautiful phenolic rocket. The thing was absolutely perfectly finished. Totally glass like. First flight, it hits a rock on landing, under chute & that was the end of that. Big chunk broken off with several cracks. Bummer.

Based on your story the speed of phenolic is about 15 fps. I don't know if an upper bound.

Actually that's not at all an unusual story. I've seen it several times. True phenolic is very stiff and very brittle. Other companies came out with phenolic hybrid materials that provide some flexibility; in fact one called their BT material "Phlexible phenolic."
Phenolic is great as a substrate for fiberglass.

 

[Dave A]

With phenolic and paper tube rockets I always take a 12" square piece of 1/2" foam and wrap it around my shock cord. Wrap it in place with electrical tape. Center it at the end of your body tube. You're less likely to zipper it. I even do this in FG airframe so the edge doesn't cut the cord in two. That can happen when deployment happens at speed.

 

[markkoelsch]

With phenolic and paper tube rockets I always take a 12" square piece of 1/2" foam and wrap it around my shock cord. Wrap it in place with electrical tape. Center it at the end of your body tube. You're less likely to zipper it. I even do this in FG airframe so the edge doesn't cut the cord in two. That can happen when deployment happens at speed.

Dave, I had been contemplating something like that, and now I have the solution. Thanks.

 

[AfterBurners]

So if phenolic tubes have so many issues why do some people decide on using them?

 

[cavecentral]

Most people glass them or use then for motor mount tubes.

Smaller rockets are ok, but large ones can't even fall over on a hard surface without breaking. Dropping a 7.5" phenolic ebay is a bad idea (from experience ).

 

[JohnCoker]

Phenolic tubes are great to work with. They cut like wood and have a smooth and hard surface. I use them in most of my projects.
Here's a comparison of available body tubes:
www.jcrocket.com/body-tubes.shtml

 

[Mugs914]

I have had good luck with unglassed GL phenolic. Unlike my experience with PML's stuff. It's easy to work with but sand areas that will be bonded. Use epoxy.

This has been my experience as well. As I recall GL was the one that called their stuff "Phexible Phenolic" and it is much more forgiving than the regular stuff. Very easy to work with...

This one is 3.9" unglassed GLPP with G10 fins. Many drops, no cracks!




I just like this pic...

 

[Bat-mite]

You might consider MAC Performance canvas phenolic. It has the dimensions of FG, but is lighter. It is also very easy to cut, drill and epoxy. Takes paint really well, too.

 

[soopirV]

You might consider MAC Performance canvas phenolic. It has the dimensions of FG, but is lighter. It is also very easy to cut, drill and epoxy. Takes paint really well, too.

I just finished a MAC P kit, and was highly impressed with the material. I haven't flown it yet, but finishing and working with it was very easy...couple of pin-hole voids in the surface, but nothing concerning. I am wondering, however, about this comment on the end of John C's review of the materials:

The MAC Performance "canvas phenolic" seems stronger than other phenolic. For example, it takes much longer to drill a hole. In terms of brittleness, it falls closer to the PML end of the spectrum and feels a lot more solid than flexible phenolic and the vulcanized paper phenolics.

I'm worried about brittle material because we never get to land on grass, it's always rocks and desert hardpan out here. This is the primary reason I don't have any PML kits in my fleet...and the MAC is just so purdy, I'd hate to ruin it!