Trimodal Mix, Pt 1

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mdutch
Posts: 72
Joined: Mon Nov 09, 2015 4:01 pm

Trimodal Mix, Pt 1

Postby mdutch » Sun Feb 14, 2016 10:46 am

Due to the scale I use I find it easier to screen and pre weight the AP to mix later in the process.
1 AP400, AP200, & AP90.jpg

Here you see the KA bowl with the R45, DOA, tepanol, and Lecithin all poured in.
2 All the liquids.jpg

Here you see me screening the Al into the mix bowl. It should be noted that you should use a dedicated screen for each chemical you use.
3 Screening and adding the Aluminum by weight.jpg


The forum is not letting me add more photos so I will create a part 2 and however many parts I'll need to add to complete the photos of the mix.
Sorry for this.
Mike Dutch
URRG & MRSI Founder
TAP L3CC
"I just want to fly ROCKETS"

mdutch
Posts: 72
Joined: Mon Nov 09, 2015 4:01 pm

Re: Trimodal Mix, Pt 1

Postby mdutch » Sun Feb 14, 2016 10:54 am

Well let's see how this works;

OK, so here you see the screened Aluminum wetting out into the liquids.
4 Al screened and wetting out.jpg

Here is the BIO wetting out.
5 BIO screened and wetting out.jpg

Now that the metals are wetted I'm mixing everything until it's a good uniform color. (about 10 to 15 minutes here)
6 Mixing all the liquids and metals.jpg
Mike Dutch
URRG & MRSI Founder
TAP L3CC
"I just want to fly ROCKETS"

mdutch
Posts: 72
Joined: Mon Nov 09, 2015 4:01 pm

Re: Trimodal Mix, Pt 1

Postby mdutch » Sun Feb 14, 2016 11:06 am

The forum is refusing to let me place more than 3 photos per post, but I can work with it, just bear with me, thanks.

With the liquids and metals well mixed I now put the mix under it's first vacuum. It is amazing just how much air you will get out of the mix by doing this now before you add your AP.
7 Putting the liquid and metals under vacuume.jpg

Now I'll start by adding the AP400, being the biggest AP particle it needs to be added first so the tepanol can completely coat it.
8 Adding the AP400.jpg

Next you add the AP90.
9 Adding the AP90.jpg
Mike Dutch
URRG & MRSI Founder
TAP L3CC
"I just want to fly ROCKETS"

mdutch
Posts: 72
Joined: Mon Nov 09, 2015 4:01 pm

Re: Trimodal Mix, Pt 1

Postby mdutch » Sun Feb 14, 2016 11:24 am

You want to mix each AP at least 10 to 15 minutes to completely blend everything. To some this may seem like a short time but I'm only making one 98mm grain here.
Also there was only a small amount of the 400 and 90. With adding the AP200 there was enough that I added it by half each time
10 Adding the AP200 by halfs.jpg

Now every thing but the curative has been added and it's all being mixed well for a good 1/2 hour to 45 minutes. It should be noted that because of using tepanol there is a strong ammonia smell coming from the mix right now. This is why I'm out in the garage with good ventilation with this mix.
11 All components added and mixing up.jpg

So now everything is mixed minus the curative. At this point I'll let this sit and relax for a good 12+ hours to give the tepanol time to react completely with the AP. You have to let this reaction happen or you will get little gas bubbles in your grains because you poured/packed too soon. (a cato waiting to happen, not good)
12 Everything Mixed and scraped down.jpg
Mike Dutch
URRG & MRSI Founder
TAP L3CC
"I just want to fly ROCKETS"

mdutch
Posts: 72
Joined: Mon Nov 09, 2015 4:01 pm

Re: Trimodal Mix, Pt 1

Postby mdutch » Sun Feb 14, 2016 5:35 pm

Actually this is now day/part 2. The mix has sat over night and I just finished pouring the grain that I was looking to get. Here are the next set of photos from the pour.

Here I've sprayed the cores and caps for the 98 mm grain as well as the 75mm over flow that I'm expecting.
14 True Core sets preped and Casting tubes wrapped and ready for propellant.jpg

OK, so now I've added the curative and mixed it all into the mix. I'm pulling my final Vac just before I place the propellant into the Ziploc bag for the pour. I'll be using a gallon freezer bag and cutting the bottom corner to pour it into the casting tube.
15 Curative added, mixed and final Vac being pulled.jpg

Here you see the 98 mm grain and the 75mm overflow grain, (it's not full). Also you see the Ziplock bag with the residual propellant left in it. What you don't see is the rolling pin I used to help coax as much of the propellant towards the cut as possible.
16 Casting tubes filled. The gallon ziplock bag was used like a pastry bag..jpg


I'll take more photos when the grain is cured and I've done my final prep on the finished grain.

You will also note that the casting tubes are wrapped with paper and blue tape in an effort to keep the finished grain as clean as possible. Even a smear of propellant on the outside of your casting tube could create a flame path that you DON'T want in your case. (again it could cause a possible cato)
Mike Dutch
URRG & MRSI Founder
TAP L3CC
"I just want to fly ROCKETS"

mdutch
Posts: 72
Joined: Mon Nov 09, 2015 4:01 pm

Re: Trimodal Mix, Pt 1

Postby mdutch » Mon Feb 15, 2016 6:16 pm

A finished 98 mm grain, 6 1/2" with a 1 1/4 core. Four more and a smoke grain and the motor will be finished.
17 Finished grain, four more and a smoke grain and I done with this motor.jpg


I could probably do two grains at a time but it would mean taking a chance that the vac would pull the propellant into the hose, gauge and or pump. Not worth the trouble, better to do one grain at a time. Or wait until I can use Dan Sheerer's 20 Qt mixer at a mix party and do all the grains at once. For now I'll make do with what I have at home.
Mike Dutch
URRG & MRSI Founder
TAP L3CC
"I just want to fly ROCKETS"

mdutch
Posts: 72
Joined: Mon Nov 09, 2015 4:01 pm

Re: Trimodal Mix, Pt 1

Postby mdutch » Fri Feb 19, 2016 12:34 pm

There was a request for a close up on the end of the grain, here it is;
IMG_20160219_122311_301.jpg

As part of that original request I don't know how to figure what the density of the mix is.
Mike Dutch
URRG & MRSI Founder
TAP L3CC
"I just want to fly ROCKETS"

JD13x
Posts: 26
Joined: Thu Feb 04, 2016 10:35 pm

Re: Trimodal Mix, Pt 1

Postby JD13x » Mon Feb 29, 2016 11:50 pm

I read (somewhere) that Lecithin has an equivalent weight.
Dutch, do you account for this?
I stopped using it in favor of Triton X-100.

JD

mdutch
Posts: 72
Joined: Mon Nov 09, 2015 4:01 pm

Re: Trimodal Mix, Pt 1

Postby mdutch » Tue Mar 01, 2016 7:51 am

I have not heard of lecithin having an equivalent weight myself, so ,no, I have never accounted for it. I've also never had an issue with my grains not properly curing. But then when all I'm using is .5% of it per batch size I don't see how it could really effect the mix in curing much at all.

I welcome differences of opinion in this matter.
Mike Dutch
URRG & MRSI Founder
TAP L3CC
"I just want to fly ROCKETS"


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