Aerotech M1780 grain bonding?

[Rocketjunkie]

Thanks Justin and those who posted above!!
So I was able to find a bottle on Amazon that had same day delivery and ordered it up. Should be here tonight. So, doing ejection tests in a few and getting things ready then doing HW till the glue arrives then prepping the motor tonight. It won't be 24hrs of cure, more so 12+ hours should be plenty.
Thank you to all that posted!!!

I ordered some from Amazon a while back. It was so old it was mostly solidified in the bottle when received. Completely unusable.

 

[Banzai88]

I ordered some from Amazon a while back. It was so old it was mostly solidified in the bottle when received. Completely unusable.

Did you get a refund or a replacement?

 

[StreuB1]

I ordered some from Amazon a while back. It was so old it was mostly solidified in the bottle when received. Completely unusable.

Lets think positive for me at this point as I am launching this rocket tomorrow, even if I have to use bungee cords!!! LOL

 

[Rocketjunkie]

Did you get a refund or a replacement?

Not worth the hassle for a <$20 order.

 

[StreuB1]

Not worth the hassle for a <$20 order.

Amazon truck is 5 stops away......lets pray its not gone bad! lol

 

[Banzai88]

Amazon truck is 5 stops away......lets pray its not gone bad! lol

 

[StreuB1]

Ahhh, its fresh!

 

[rfjustin]

Ahhh, its fresh!

Its been 47 minutes, you done yet?

 

[StreuB1]

Its been 47 minutes, you done yet?

Oh yeah, been done. I always need to take half my house with me whenever I go launch rockets or to the range. Its ridiculous. Even when I prep my rockets and motors ahead of time.

Glued up the L1520 without any issues. That method in that video where you tape all the grains and orings together as an assembly and then slather and stuff ( ) is the way to do it. Super easy and barely any mess at all.

Assembled a J800 as well; favorite motor along with the K1100. Looks like tomorrow is a blue thunder day.

 

[jbr]

if you don't follow the instructions to the letter, there is NO WARRANTY

use the glue specified, Gary worked on these reloads for 10 years and use a different glue and boom

your choice

 

[Rocketjunkie]

The last time I flew a L1520 was before all this gluing in the grains. Never glued in the grains. If you are flying a light rocket with high acceleration, that is when you need to glue in the grains.
Glad that you got fresh glue.

 

[sharkbait]

if you don't follow the instructions to the letter, there is NO WARRANTY

use the glue specified, Gary worked on these reloads for 10 years and use a different glue and boom



your choice

if you don't follow the instructions to the letter, there is NO WARRANTY

I have used Elmer glue all max, West Systems, U.S. Composites, Aeropoxy, Gorrila, and Tite Bond, no issues. I use silicone caulk now on everything, No Boom, so if they stop making Elmers glue all max, you will still be able to bond grains and fly without Boom

use the glue specified, Gary worked on these reloads for 10 years and use a different glue and boom

your choice

 

[Antares JS]

One more question... now that I have my 75mm motors and my glue-all max and am looking to bond them, it occurred to me that the bonding instructions don't say anything specific about applying some water to cure the polyurethane glue. I am thinking of just dampening the inside of the liner a bit as I clean it out. Does that work?

I probably am worrying too much but I really don't want to mess up these expensive reloads.

 

[jbr]

the humidity in the air does it, water would make it foam too much

 

[UPscaler]

One more question... now that I have my 75mm motors and my glue-all max and am looking to bond them, it occurred to me that the bonding instructions don't say anything specific about applying some water to cure the polyurethane glue. I am thinking of just dampening the inside of the liner a bit as I clean it out. Does that work?

I probably am worrying too much but I really don't want to mess up these expensive reloads.

No need! Just be sure to get a consistent amount of glue on the casting tubes and be careful not to get it on the faces.

I have a video assembling both a 75mm and 98mm load that required bonding if you want to see how it's done. I'm no sort of expert or anything but getting a visual idea always helps.



There's still plenty of hot debates about using Gorilla Glue (which is also polyurethane and only gets extra foamy when its wet, just like the Elmers stuff), but that's not an issue since you have the Glue-All. Don't stress about it too much! You've got it.

Braden

 

[Antares JS]

Thanks, I really appreciate the help.

 

[StreuB1]

Mine that I did for the Nov 20th launch foamed up quite a lot about 2 hours after assembling the liner/grains/nozzle and started oozing out the nozzle/liner intersection. So be sure to keep an eye on it and put it on a few sheets of paper. The ambient humidity in the house, even in the dry cold midwestern air, was enough to get it to go off no problem.

I used the scotch tape, vertical stack method in the video below and it worked perfectly. Just make sure to test fit your grains first to make sure they fit easily. Mine were a sliding fit so no issues. You also don't need to "slather" the glue on and get crazy with it. A nice skim coat over the entire stack is enough. Some say its crazy messy. Personally, I only got glue on a single finger that was used to spread it around. I just kept it upright and tipped it at an angle and drizzle glue down the side and then smoothed it around. Kept doing that till it was all coated and then slid the liner over it all. Picked it up and pushed the grain stack in for the nozzle to clear, wiped the end of the liner out, installed the nozzle, placed it nozzle down, pushed the grains down against the nozzle end, wiped things up and let it cure standing up next to me on the computer table. Had to wipe the ooze here and there but it was easy as could be. Kept an eye on it for 3-4 hours and then went to bed. Woke up and it was a solid assembly.

I went into it thinking it was going to be a lot of drama but it literally took me 10min to complete and zero dramas.

 

[tjsnakez]

Like other have said, a light coat of glue is all you need. I spread it with a gloved finger until it's shiny. The humidity in the air is enough to cause it to foam. I always use gorilla glue without issue, but it is possible to crack the liner if you apply it too thick. The Elmers foams a little less, so it is less likely to cause problems, which is why it is now recommended by the manufacturers. I would do it a grain at a time like the instructions state. Forward grain first and nozzle grain last. It's nerve racking the first time, but it's not as hard as it sounds. You got it!

 

[Antares JS]

Looks like everyone was right - I was worrying about it and it turned out to be no problem. I bonded my K1000T last night and took the nozzle off this morning and gave it a few shakes to make sure the bonding took, and all seems well. Thanks for the help.

 

[StreuB1]

Looks like everyone was right - I was worrying about it and it turned out to be no problem. I bonded my K1000T last night and took the nozzle off this morning and gave it a few shakes to make sure the bonding took, and all seems well. Thanks for the help.

View attachment 496739

Excellent!

What process did you find worked best for you? The grain at a time method or the taping the grains/orings into a tower method?

 

[Antares JS]

Excellent!

What process did you find worked best for you? The grain at a time method or the taping the grains/orings into a tower method?

The grains slid freely inside the liner so I decided to do it a grain at a time so I could hold the tube horizontally.