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JB weld?

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Hey everyone! Im a BAR and am now just moving into MPRs. Im currently building an AT Mustang and from what I have read it should be a good intro rocket. My question is if anyone has used JB weld for building instead of epoxy. Ive used it on other hobby projects and it worked great. If not, what is the recommended epoxy for fillets and general on MPRs. I just got my AT rms 29/40-120 case ,so i guess my next question would be what is a good reload for the mustang?
 

Missileman

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Hello and welcome to TRF.
I personaly use 5 minute epoxy on fin roots and details just to get things in place with a fast set time and then I use 20 minute finish epoxy for fillets and motor mounting, centering rings ect..
I tend to build heavy.
Some people mix micro balloons into their epoxy for fillets to cut down on weight.
I have heard of JB weld being used but have not tried it myself.
I think, but am not sure, that JB Weld is a bit heavier than epoxy.
Can't comment on motor selection as I don't have a Mustang.
Best of luck
 

Dwight

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I am new to Mid-power myself, however I have been building all my model kits with Epoxy from day one.

Micro Balloons and milled fiber are not to make the epoxy lighter ( although that may be a sideline benefit ) but those substances mixed in with epoxy can increase the strength of the bond by up to 300%

It also has the added benefit of thickening the epoxy so it is easier to shape for making fillets.

I have not used JB wield, I am using the standard hobby Shop epoxy and adding milled fiber as needed or to thicken and strengthen it for certain joints.

With a little care you will find that while epoxy can be annoying, it is in some odd ways easier to use than other glues.

You can determine its properties yourself, use 5 min or 12 min or 30 min ( warning, 30 min only starts to set up in 30 min, it does not cure fully for several hours ) I build Estes models with 5 min epoxy, that gives me enough time to carefully place a part, while never having to hold it in place longer than 5 min and ends up with a bond stronger than CA.

On Mid power models I am sticking with 12 and 30 min Epoxy, but I am using milled fiber as an additive. You can determine how thick and strong it is with milled fiber or micro balloons.

Personally I have come to like the way I can control epoxy so much that it is the only glue I use even on the small models.
 

hokkyokusei

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Originally posted by letfreedomring
Im currently building an AT Mustang and from what I have read it should be a good intro rocket. My question is if anyone has used JB weld for building instead of epoxy.
Doesn't the AT Mustang recommend CA for construction? I know the HV ARcas does.
 

Dwight

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Instructions? We don’t need no stinking instructions!

( actually I have never built an Aerotech kit, I wouldn’t know )
 

Hospital_Rocket

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I would think JB Weld on an Aerotech would be massive overkill. Considering you can almost dry fit it and fly it. I would not have the 18-24 hour patience to wait for set up. I do use JB Weld on Aeropack retainers as specified,

JB weld is an ultra high strength epoxy originally used for hydraulic repairs. It is all but indestructible once set.
 

Larry

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Yes, the aerotech kits can be built with CA. My first Initiator was built that way and is still going strong. The way these kits are put together I think you could almost leave the glue out:D
I would suggest going with the instructions, but if you want to add fin fillets then do so. I use JB weld as fillets on all my rockets anymore. I can get it at a reasonable price ($2.99).It doesn't take alot and I've never had a fillet crack yet. I like it because it gives you lots of time to work with it and it stays put. You have time to make real smooth fillets so you don't need lots of sanding. It does sand pretty nice also.

letfreedomring,
You will like your 40/120 rms, and although I don't have the Mustang I'm sure your going to really like it as well. You should have a pamphlet called the motor matrix in your kit. It will give you suggestions on what reload and delay to use, also has SU motor suggestions. Guys here can tell you also what they have used. Good luck, and don't forget the pictures OR ELSE!!:kill:

Larry
 

astrowolf67

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The Mustang goes together just fine with CA as per the instructions. JB weld would be overkill, not to mention the wait time while drying. As far as epoxy goes, I use the cheap stuff from Wal Mart, either 5 minute, or the 2 ton stuff.

For motors for the Mustang using the 29 40-120 case, the AT Motor Matrix lists:
E16-7 950ft
E23-5 800ft
F40-10 2250ft
F22-7 1700ft
F52-8 2100ft
G33-7 2650ft
G64-10 3200ft

First flight, I'd go with the E16, although a 7 second delay seems a bit too long unless wind conditions are ideal.
 

MarkABrown

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Originally posted by Dwight
I...Micro Balloons and milled fiber are not to make the epoxy lighter ( although that may be a sideline benefit ) but those substances mixed in with epoxy can increase the strength of the bond by up to 300%...
Actually, only milled fiber adds strength. Micro-Balloons reduce strength significantly but makes the epoxy more sandable.

I think JB Weld is overkill on a mid-power kit. It will add tremendously to the weight. I'd go with CA for most construction and use 5 min hobby epoxy for fillets.
 

loopy

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All AT kits can be built with CA as recommended and hold up fine. I've built all mine with CA, but then (mostly for appearance and paranoia) put epoxy fillets on the CR-body tube joints, and on the fin joints as well. Just kinda smooths out the transition and adds a little insurance.

Loopy
 

rbeckey

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I recently discovered that JB Weld can be softened by Zip paint remover. I let it soak in for a couple of hours and it became pasty and easy to scrape away.
 

Dwight

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Interesting information about micro balloons, Now I dont need to bother buying them. I only planned to use milled fiber anyway.

Of course my goal is a very strong rocket, one that will perhaps survive some forms of recovery failure. Hence the use of only Epoxy as a glue and the additive.

Time is simply not a factor for me. I never need to build a rocket in a hurry. The goal is to build it right, not just right now.
 
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