Another Inherited Hot Mess

[Kruegon]

As with my inherited Velociraptor, I am receiving an inherited PML AMRAAM 4. This rocket has G10 fins and a quantum body tube.

I've been told it's a full, ground up, rebuild like the Velociraptor. Strip paint, cut out fillets, fin work, possibly even going to need to rip out the MMT and install a new one. With all that in mind, I need advise on adhesives.

What can successfully bond G10 to quantum tubing? I understand that quantum can be very difficult to bond properly.

 

[CoyoteNumber2]

Why do you need to tear apart a rocket and rebuild it? Wouldn't it just be easier to start with a new kit?

Public Missiles recommends plain epoxy for bonding to Quantum Tube.

 

[bclark989]

I built a PML Explorer with those materials. I used the Loctite Plastic Bonder and took it to mach 0.96 on its maiden flight with no issues. It is a 20 minute formula, and was super ideal to work with for fillets.

I will say that per the spec sheet, this particular formula of theirs is only rated up to 180°F, so I'm not sure how it will age on the joint to the MMT tube. For fillets, its probably fine. It was also the worst smelling epoxy I've ever used.

Sounds like a fun project, good luck =)

 

[tim cubbedge]

I've used epoxy on all my quantum tubes with zero failures. Just scuff up the tubing a bit just like you would with fiberglass.

 

[Graduator]

I've built several QT kits and scratch builds. Any decent epoxy will work (West, Bob Smith, generic 15 Min. hobby store brand). Just make sure you prep it reasonably well. Nothing special, just roughen surface with 80-120 grit sandpaper and wipe completely clean with alcohol before gluing. It's not porous like cardboard, so it's all about the bonding surface, just like fiberglass tubing. I have even used JB Weld with great success. Sure, it's expensive and a bit heavy, but it does make nice fillets that have never cracked for me. A few other tips about QT. It does expand and contract with temperature changes, and becomes brittle as you approach freezing. I avoid the piston, but others seem to like them.

 

[dmjung]

I've used West System epoxies without any issues, but make sure you absolutely rough up the QT thoroughly at the bonding areas. I can imagine issues with smooth or almost smooth QT.

 

[mpitfield]

As others said you will have no issues with a decent epoxy so long as you scuff up the QT first, I would us 80 grit and scuff it up well.

 

[Kruegon]

Why do you need to tear apart a rocket and rebuild it? Wouldn't it just be easier to start with a new kit?

Public Missiles recommends plain epoxy for bonding to Quantum Tube.

Because it's $25.00 for the rocket as is.

 

[Kruegon]

Thanks guys. I have heard QT was difficult to bond properly.

 

[CoyoteNumber2]

Because it's $25.00 for the rocket as is.

Ok, but why go through the trouble of disassembling instead of just flying it? If you're going to build a rocket piece by piece, why not start with a fresh kit? I guess I don't understand. Is it just a "enjoy the challenge" thing?

 

[Kruegon]

Well it wasn't built correctly for one.

Second, it's considerably cheaper this way.

Lastly, yes, there is a great amount of personal satisfaction in taking something that is a$$ed up and probably wouldn't pass the RSO and making it something that people would envy.

Before, during, and after pics are always a must.


I'm currently working on a $200 kit. I paid $15 as is, ordered $20 in parts, a couple of bucks for supplies (most I already had) and I get a miraculously beautiful bird that most anyone would be proud to own. Time and elbow grease cost me nothing extra.

 

[K'Tesh]

Well it wasn't built correctly for one.

Second, it's considerably cheaper this way.

Lastly, yes, there is a great amount of personal satisfaction in taking something that is a$$ed up and probably wouldn't pass the RSO and making it something that people would envy.

Before, during, and after pics are always a must.


I'm currently working on a $200 kit. I paid $15 as is, ordered $20 in parts, a couple of bucks for supplies (most I already had) and I get a miraculously beautiful bird that most anyone would be proud to own. Time and elbow grease cost me nothing extra.

AND it keeps a rocket out of a landfill for a while longer.

 

[CoyoteNumber2]

Well it wasn't built correctly for one.

Second, it's considerably cheaper this way.

Lastly, yes, there is a great amount of personal satisfaction in taking something that is a$$ed up and probably wouldn't pass the RSO and making it something that people would envy.

Before, during, and after pics are always a must.


I'm currently working on a $200 kit. I paid $15 as is, ordered $20 in parts, a couple of bucks for supplies (most I already had) and I get a miraculously beautiful bird that most anyone would be proud to own. Time and elbow grease cost me nothing extra.

Ah, cool. Good luck!

 

[Kruegon]

Sometimes a failure can be a reason to make it bionic.

"We can rebuild it. Make it faster, stronger, than it ever was before."

My big daddy that lawn darted is getting the bionic treatment. I have spare 1/8" plywood and spare 3" Estes tubing. It's getting a nose cone mod with a/v bay, plywood fins and centering rings, and a 38mm MMT.

May only be 1 grain cases, but it's a ~20" rocket on a 38mm motor.

I'm finding a new love of rocketry in rebuilds.

 

[Kruegon]

I've been building a list of needed parts for the AMRAAM rebuild. New centering rings. Replacement MMT. New coupler for the a/v bay.

I've run into a small snag that I'd like suggestions on. Whomever built it originally, did so by the base design. The phenolic coupler has been adhered into the upper section with the bulk plate epoxied inside.

I understand why, but it isn't conducive to dual deployment. Any suggestions on how to remove a phenolic coupler from the quantum tube airframe? I do not care about the coupler. I already consider it trash. The bulk plate is trash as well. I just need to get it out so I can slick the tube.

 

[cbrarick]

peel the inside as much as you can then break out the dremel.

 

[gerbs4me]

Good luck on the project!

Glad you save the rocket from the landfill

 

[grouch]

You could just cut off the bulk plate and use the glued in coupler for the ave bay. Drop the sled and upper bulk plate down the upper tube and bolt the bottom bulk plate on. Works.

 

[Binder Design]

Lastly, yes, there is a great amount of personal satisfaction in taking something that is a$$ed up and probably wouldn't pass the RSO and making it something that people would envy.

Yep. Restoration of old cars comes to mind here too.

 

[Kruegon]

Yep. Restoration of old cars comes to mind here too.

Well you know, I'm not done with that Velociraptor rebuild yet. Stripping the sustainer has proved much more challenging than the upper tubes. Plus life. I'm about 1/2 done stripping on the sustainer and 90% complete on the upper. I'm hoping to work on it this Sunday while I wait for primer and epoxy to dry on other rockets.

I've got 3 months to paint roughly 2 dozen rockets ranging from 13mm to 4". I have 2 to assemble and paint. I have 1 to complete the restoration on and paint. There's my wife's L1 that she'll need advice and follow up on. Then I get to paint it. Then this second strip and rebuild. I doubt this one will make NSL. Too much on my plate. I need to start prepping for Southern Thunder 2017 the day after NSL it seems.