Internal fillets—E120 HP?

[duodenumnums]

Hi all, I know there’s a hundred different adhesive threads but I can’t find much about Loctite E120-HP (or its generic equivalent, Infinity Bond EP 120). I’m building my first high performance rocket (Wildman Shapeshifter 75) and I don’t really plan on building another big fiberglass one anytime soon, so I don’t want to spend the money and shop space on a “system” like West Systems or Aeropoxy. I recently heard about E120-HP and it sounds thin enough to easily make internal fillets; can it withstand the heat and stress of an L motor? I’ll be using JB Weld to tack on the fins.

 

[tfish]

E120-HP would be over kill.

JB weld would work well as would other 20-30 min (non laminating) epoxies.

Save the E120-HP for Min dia ,over mach 2.5 rockets..

Tony

 

[Neutronium95]

That's a really high performance epoxy intended for use in engineering applications. It's absolutely overkill, and will probably also be murder on your wallet.

Any halfway decent epoxy will be fine for building that kit.

 

[duodenumnums]

That's a really high performance epoxy intended for use in engineering applications. It's absolutely overkill, and will probably also be murder on your wallet.

Any halfway decent epoxy will be fine for building that kit.

Thanks everyone. I guess I got a little worked up reading those other epoxy threads and worrying that a high K or an L would break it apart.

JB is too thick for spreading internal fillets, at least for me. Will 30 minute Bob Smith hold up?

 

[rfjustin]

Hi all, I know there’s a hundred different adhesive threads but I can’t find much about Loctite E120-HP (or its generic equivalent, Infinity Bond EP 120). I’m building my first high performance rocket (Wildman Shapeshifter 75) and I don’t really plan on building another big fiberglass one anytime soon, so I don’t want to spend the money and shop space on a “system” like West Systems or Aeropoxy. I recently heard about E120-HP and it sounds thin enough to easily make internal fillets; can it withstand the heat and stress of an L motor? I’ll be using JB Weld to tack on the fins.

E120-HP is really thick and would not be a great choice for internal fillets. I get it, West Systems kits can be spendy, but they are worth it, get a quart system kit and have it.

 

[NTP2]

looking at the title I thought you were talking about making a E120… as in a HP rocket motor…

 

[duodenumnums]

E120-HP is really thick and would not be a great choice for internal fillets. I get it, West Systems kits can be spendy, but they are worth it, get a quart system kit and have it.

Which hardener and additives do you like to use?

 

[rfjustin]

Which hardener and additives do you like to use?

For most work, I like West 205 Fast hardener, and milled fiberglass to thicken as needed.
https://www.totalboat.com/products/milled-glass-fiber

 

[Donnager]

If you would like a syringe application, I'd point you to either Loctite/Henkel Hysol E20 or E60. The 120 is a little slow for me. I use the 20 on assembly and the 60 on fillets. All are expensive.

There's a couple of 3M products that are similar. DP420 comes to mind and also uses a mixing syringe application. I've used all of these, and they work well.

 

[kswing]

You may want to take a look at T-88 from West Systems. It has worked well for me both on fiberglass and cardboard rockets. You can buy it in smaller quantities from Amazon.

 

[charrington]

I really like E120hp. I pretty much use it for everything now but most of my stuff is MD or close to it. Its extremely strong stuff but it is expensive. I also find it quite runny when cured with heat. Gotta do 1 filet at a time.

 

[rfjustin]

I really like E120hp. I pretty much use it for everything now but most of my stuff is MD or close to it. Its extremely strong stuff but it is expensive. I also find it quite runny when cured with heat. Gotta do 1 filet at a time.

What is the advantage of curing it with heat?

 

[charrington]

What is the advantage of curing it with heat?

it brings the set time from 2 hours down to like 20-30 minutes. It also improves the physical properties marginally.

 

[kjhambrick]

I really like E120hp. I pretty much use it for everything now but most of my stuff is MD or close to it. Its extremely strong stuff but it is expensive. I also find it quite runny when cured with heat. Gotta do 1 filet at a time.

Which dispensing system do you like best ?

Thanks

-- kjh

 

[charrington]

Which dispensing system do you like best ?

Thanks

-- kjh

I use the small 1.69fl oz cartridges that require a dispensing gun and mixing nozzles. If you plan on doing larger kits id highly recommend getting the larger cartridges and larger dispensing gun. The small one I use becomes a pain even on 2.6 inch kits. You can order these on Mcmaster.