Can't get lift!

[Xzanth]

Unless the non-kiln dried wood is really green, it won't matter if the wood is kiln dried or not. Even if the wood is really green, it will just take longer to cook (in a retort anyways) and you will lose considerably more weight when it's done. My willow is black willow. I don't know what weeping willow would be like; it might be worth a try to make a small batch and test it out.

I'm also gonna go ahead and try mesquite xD if anything there is alot of it around. Too much actually

[stix]

Here's some extensive tests done with various charcoals. http://www.wichitabuggywhip.com/fireworks/charcoal_tests.html

Our esteemed forum colleague Lloyd and his "Sponenburgh mill" gets a mention.

 

There's also this from pyrodata http://pyrodata.com/chemicals/Charcoal

 

Unless the non-kiln dried wood is really green, it won't matter if the wood is kiln dried or not. Even if the wood is really green, it will just take longer to cook (in a retort anyways) and you will lose considerably more weight when it's done . . .

 

That's what I thought too Mat, but I've heard contrary views on this forum. A while back I did a small (dry/wet) comparison test with "plum". It sizzled and gave off more smoke and took longer, but I couldn't determine any noticeable difference.

Edited April 9, 2016 by stix

[Xzanth]

I don't see mesquite in that list. I do see cottonwood, doeant look like it was strong. There is alot of cottonwood trees here in cottonwood arizona. Haha^-^ I'll try that and try to gauge it and video and all that..

 

Edit: oh I see mesquite in the other list. It's unsure. And I see cottonwood being very suitable . nice. I'll try for myself

Edited April 9, 2016 by Xzanth

[Xzanth]

https://youtu.be/wT1bEJXXaww

 

Ok with new charcoal. Gonna mill it for a little more but this is what i got. Screen it with a lil water? Also I think the paper was a little heat sensitive

 

Milled for about 3 hours

 

Also I think I got the paper with the torch a little

Edited April 9, 2016 by Xzanth

[OldMarine]

That didn't look too bad!

[Xzanth]

Think I should screen it to strengthen it up? I'm gonna mill it for a few more hours. See if that ups it. But yeah. Feelin better about this one.

[stix]

Yeah that last test looked better than the first. More a "fwhoomp" than a "whoosh" - looking good. A few extra hours milling would improve it even further I would think.

[MadMat]

That last test looked real good. By George, I think he's got it! haha

[Xzanth]

Should I dampen and screen it though( no dextrin) or leave it as the powder?

[Arthur]

The UK traditional guide to woods for charcoaling is; sticks from the size of a man's thumb to the size of his forearm from new growth of a tree that grows quickly by water.

 

This may infer that desert trees are poor choices. You need to have a consistent process then try some of each type of charcoaled wood.

 

If you take wood from the tree then you have to dry it first before it will charcoal -much steam and weight loss and lots of fuel used. If you have time to let the wood dry then you will use a lot less heat to turn it to charcoal.

[stix]

Should I dampen and screen it though( no dextrin) or leave it as the powder?

 

I'm not a bp expert. The motors I make these days are r-candy, so I can only speak in general terms but I'm sure many others will give better details. Unfortunately I can't remember what your exact methods are, so sorry if you have a few "derr" moments.

 

Using approx. 25/75 Alcohol and water in a spray bottle, you mix by hand the milled powder into a "hard dough". This helps to incorporate the ingredients because the water will slightly dissolve the KNO3. The Alcohol helps the water to break though any oils and allows the ingredients to absorb into the charcoal - or something like that. The dough is then pressed through a screen into granules and allowed to dry.

 

I use 3% dextrin for "lift" powder for use in a star gun. The dextrin make the granules hard which is good because I don't want them breaking back down into powder. This is useful because if the granules are consistent then you don't need to weigh it, and can be confident using a small measuring cup.

 

For what you are doing (pressing motors) you don't need dextrin, all you need is to hold the the powder together (small granules) and this makes it easier to press because it reduces the amount of dust.

 

It's also very important to let the fuel dry. I've noticed that you have done a lot of tests in the last few days which is to be commended, but have you "really" let the fuel dry properly? It usually takes a few days. This could account for some of the residue you are seeing.

 

I'd suggest that you reserve some of your test mixes, take notes and put it in a safe place to dry for 3-4 days. I reckon you will see a noticeable improvement.

 

Cheers.

[stix]

. . . If you take wood from the tree then you have to dry it first before it will charcoal -much steam and weight loss and lots of fuel used. If you have time to let the wood dry then you will use a lot less heat to turn it to charcoal.

 

Ahh! yes Arthur, that does make sense - why would you want to use more fuel to cook it than necessary? That's the best explanation promoting the benefits of using pre-dried wood vs wet that I've read. Or are there real "chemical" transformations that take place that I'm unaware of?

[Arthur]

Log ex chain saw say 10 lbs

That log split by axe and dried as sticks 5 lbs

Those dried sticks charcoaled in a can 2 lbs

 

You will likely get the same weight of charcoal but use much more fuel if the wood is wet like live wood or dry like kindling sticks.

[MadMat]

I have had bad luck with bp rockets, so now, only make rcandy rockets. I do however, make a lot of bp for shell lift and break. If you want to add dextrin to your bp, 3-4% is a good starting place. Using alcohol with the water has a couple purposes. The major one, is the fact that added alcohol inhibits the potassium nitrate from dissolving in the water. If the potassium nitrate dissolves, it will recrystallize as it dries. The slower the water evaporates, the larger the KNO3 crystals will be. This will effectively ruin what you accomplished during your ball milling. But, be aware, if you go over 25% of alcohol with your water you start to ruin the effectiveness of dextrin's binding action. Personally, I don't add any binder to my bp. I slightly dampen the bp with approx. 40/60 alcohol/water and press it in a cylinder with cast polyester resin pistons. Don't let anyone tell you you need dextrin or some other binder to make hard grains. If I don't break up the resulting "pucks" of bp before they are dry, they are hard enough to "clink" like porcelain when tapped together.

[Xzanth]

Damn I used only water. But it's in the desert sun so should dry fast.

 

Even still. I used only water hope it's OK.

Edited April 9, 2016 by Xzanth

[MadMat]

As long as you didn't use too much water you should be fine. Most people measure out their water at 3%. After making a bunch of batches, I don't bother measuring anymore. I use a trigger spray bottle (spraying gently!) and wet it just to the point that it doesn't raise up any dust and begins to get a hint of lumpiness when stirred.

Edited April 9, 2016 by MadMat

[Xzanth]

As long as you didn't use too much water you should be fine. Most people measure out their water at 3%. After making a bunch of batches, I don't bother measuring anymore. I use a trigger spray bottle (spraying gently!) and wet it just to the point that it doesn't raise up any dust and begins to get a hint of lumpiness when stirred.

Yeah that's what I do, and did for this one

[Xzanth]

https://youtu.be/mBFTIZGldfI

After milling for a lil longer and screening/quick Arizona sit in my hot car drying.

[MadMat]

Looks good

[lloyd]

Xzanth,

That's MUCH better. The large particles seem to still be spraying off that mass. Well-milled powder with good charcoal would hardly make a central "smudge", with 'rays' extending out, but not those larger burnt spots.

 

But you're getting there!

Lloyd

[Xzanth]

Yeah I'm using these 2x2 pine wood still. It's what I cooked on the tlud. Got red cedar on the way though. Then we'll see.

[DavidF]

Xzanth, one thing that I think has not really been made clear to you in this thread is how much you can expect to lift with this tooling. No matter how good your powder is, you will not be lifting 2.5lbs with a 1lb Wolter end burner set. With the most powerful powder with the most powerful tooling (NOT end burner), you would still be lucky to to that!

 

So, what are your expectations, since we KNOW you cannot do what you propose to do?

 

If you use an Estes D12-3, you will not be lifting 4 inch ball shells very high. A heavy 4" shell might weigh a pound. That shell would probably not make it 50 feet. It would be realistic for you to expect to lift a 3" ball shell with your motor, once you have your issues worked out. Hand-ramming puts way less pressure on the propellant than pressing, so you get way less propellant in your motor. IF you could make a 1lb end burner motor as powerful as an Estes D12-3- but you can't- it would be nowhere near what you need to lift your 2.5 pound rocket. An Estes D12-3 has about 2 1/2lbs of average thrust, which is WAY less than what it would take to lift a 2.5lb object of any kind.

 

Someone may mention that your 'elongated' spindle will give more initial thrust than a 'regular' Wolters 1lb end burner spindle. No matter. It still can't be done.

 

So, while the advice on how to make better powder is certainly good, your goal needs to be changed. I would say that even using a well-made, pressed 3lb end burner motor is not enough for what you hope to achieve. I don't mean to discourage you. I just didn't want you to think that if you only tried hard enough, you could lift that rocket. Not with 1 motor, anyway

[Xzanth]

I'm gonna make a rocket that I'm hoping to go for 3/4 lb. The ones I were making were 2-3 ft high lol. But I'm working on a smaller 10 inch rocket with all lightweight stuff. I'll see what I get. Also going to drill up into the hole a little more (by hand, and with my gloves) to get a better start. I wax all my tubes to lessen CATO possibilities.. It's all a work in progress. Can't start off a grandmaster. Gotta work with what I got to get a better understanding. Thanks I'll keep all this in mind. I appreciate it

[Xzanth]

 

Someone may mention that your 'elongated' spindle will give more initial thrust than a 'regular' Wolters 1lb end burner spindle. No matter. It still can't be done.

 

Not the spindle, the nipple was incorrectly machined and is an inch long before the spindle even begins. What they did was sent me a ring thing to put over it. Meh..

[Mumbles]

This is looking good. You're definitely getting there. Also, wetting with water will still give good product. Harder grains from water + dextrin does have its advantages in certain situations. It's not always about pure speed.

 

I don't know if anyone has ever done any side by side comparison between dried or fresh wood. It'd be an interesting experiment. I suspect there is a difference, but have no idea which way that would lean. Dried wood is easier and faster to cook, as well as giving higher relative yields.