what am i doing wrong

[ST1DinOH]

well i managed to get a decient pasteing done on my first batch of 3's and 1.75's but it was a huge PITA and they wound up looking horrible.

 

the pic of the single 3 is probably the best one.

 

http://img178.imageshack.us/img178/3924/13inchshellpastedfp9.jpg

http://img116.imageshack.us/img116/3750/175shellpastedbs9.jpg

http://img116.imageshack.us/img116/5447/33inchshellspastedum6.jpg

 

the process i used was as follows...

 

cut strips of grocery bag, soaked in 50/50 elmers glue and water, over a heavily fiber taped shells.

 

the problem i had was the damn paper would slide all around the hemi's and i could never get it to lie flat or adhere propperly due to the slick surface of the fiber tape.

 

any suggestions or a list of everythingi screwed up would be wonderfull...

 

i just built a few shells last night but i'm dreading another messy stressfull pasting venture...almost reluctant to finish them off properly because i was so annoyed the last time.

 

also is it just me or do my shells look like a bad mummy costume from halloween?

[k1ley4evr]

hmm perhaps try it without the fibertape. it does look like a mummy lol.

[ST1DinOH]

hmm perhaps try it without the fibertape. it does look like a mummy lol.

lol...hey sup k1ley

 

i thought that fiber tape is good to have to give it a good break.

 

i completely covered the shell in that tape, row by row, overlapping by 1/3 of a strip on each pass. when i was done the thing was rock solid.

 

can i get by with just taping?

 

or can i do just fine with no tape and all pasting?

 

i was under the impression that doing both was the way to go.

[k1ley4evr]

im pretty sure itll be good if you just do the tape. Alot easier too. Was it all even after you taped it? We really gotta get together for a shoot man. Couldnt make it to lemas. Those buzzballs are badass btw.

[ST1DinOH]

im pretty sure itll be good if you just do the tape. Alot easier too. Was it all even after you taped it? We really gotta get together for a shoot man. Couldnt make it to lemas. Those buzzballs are badass btw.

if tape is sufficinet i'd so much rather do that. i got real good at taping them. i made sure to have the overlaps on the top and bottom so there was no unnecessary expansion of the OD of the shell. all vertical runs of the tape and like i said i went methodicly around the shell multiple times till it was completely covered. they looked real good till i mummified them.

 

and yeah man sooner or later we'll be able to get together for a group shoot. gotta try for sometime this spring or summer. i need a place to test out my new shells so if you hear of anything let me know.

 

in order to test these buzzball shells for the first time i'm going to need someplace thats wide open. i'd hate to see them fly longer than i suspect and wind up hitting the ground whiel still flying. from the ground up they tend to fly about 100 feet...but propelled downward from a break, with the prime delay, and if they start off flying downward...

 

that could be bad.

 

i've got lots of tests to do with these things, and i'm gonna have to overload the lift a bit to make sure they get up higher than the typical 3 just to be safe.

[rocket]

What you could do and I have done this with plastic shells is add a layer of masking tape over the fiber tape and past onto that, the paper wont slide around on it.

[qwezxc12]

ST,

 

Coming from the perspective of someone who's made many a fiber-taped RAP shell, I doubt the additional paper pasting is doing anything significant for your shells (from a performance perspective)

 

Let's look at the math:

Generic fiber tape, .006" thk at McMaster-Carrr has a tensile of ~150lbs./in. width. I'll guess that you're using 3/4" tape so call it 100lbs as a very conservative estimate. With three overlapping layers (effectively 6) completely covering your shell you have 600lbs tensile.

 

Pasted-in 60lb. grocery bags strips tested out at 19lbs./in. tensile, averaged with and across the grain (yet another reason to subscribe to Passfire). If you give the shell the same treatment (3 overlapping layers of 3/4"), that equals 86 lbs additional tensile.

 

That's less than 13% additional strength, or less than half of only one additional wrap of tape. And (no slight on your workmanship - pasting is a pain and an aquired skill) the paper would only yield optimum numbers if pasted in smooth and tight. By the looks of your pictures, the paper layers look like they have voids and may not adhere firmly enough to really add all the strength they could.

 

Unless you're really wanting the added "traditional" look of paper, I'd pass. If you want the paper, try some lighter kraft...say 30lbs with a thinner glue mix or wheat paste. 6 layers of that will go on a lot easier than 3 layers pf grocery bag..

 

FWIW, for my 3in shells, I use only fiber or masking tape. I use gummed tape on 4in and larger now.

[ST1DinOH]

What you could do and I have done this with plastic shells is add a layer of masking tape over the fiber tape and past onto that, the paper wont slide around on it.

 

damn...i never thought of that. that's a great idea. thanks.

 

ST,

 

Coming from the perspective of someone who's made many a fiber-taped RAP shell, I doubt the additional paper pasting is doing anything significant for your shells (from a performance perspective)

 

Let's look at the math:

Generic fiber tape, .006" thk at McMaster-Carrr has a tensile of ~150lbs./in. width. I'll guess that you're using 3/4" tape so call it 100lbs as a very conservative estimate. With three overlapping layers (effectively 6) completely covering your shell you have 600lbs tensile.

 

Pasted-in 60lb. grocery bags strips tested out at 19lbs./in. tensile, averaged with and across the grain (yet another reason to subscribe to Passfire). If you give the shell the same treatment (3 overlapping layers of 3/4"), that equals 86 lbs additional tensile.

 

That's less than 13% additional strength, or less than half of only one additional wrap of tape. And (no slight on your workmanship - pasting is a pain and an aquired skill) the paper would only yield optimum numbers if pasted in smooth and tight. By the looks of your pictures, the paper layers look like they have voids and may not adhere firmly enough to really add all the strength they could.

 

Unless you're really wanting the added "traditional" look of paper, I'd pass. If you want the paper, try some lighter kraft...say 30lbs with a thinner glue mix or wheat paste. 6 layers of that will go on a lot easier than 3 layers pf grocery bag..

 

FWIW, for my 3in shells, I use only fiber or masking tape. I use gummed tape on 4in and larger now.

 

WOW

 

i ask for advice and i get tinsile strength comparisons...that was awsome. thanks bro.

 

not sure if this makes any difference but i've been using the real thin tape, about 1/2 inch wide. i usually overlap on each pass and wind up going all the way around the shell a little more than one time. this way there isn't any part of the shell that isn't covered in fiber tape.

 

i'd call that one layer.

 

that layer is going across the seam of the two hemis from pole to pole if you consider the fuse hole as the "north pole"

 

would i be doing myself a favor to then add a second layer going the other direction (latitude)?

 

then another layer north to south?

 

or is that one layer of fiber tape good?

 

and yeah, i only added the paper in an attempt to make them look good. if fiber tape is better then why go through the mess and aggravation just to make them look good.

 

thanks again.

[TheSidewinder]

I think that's one of those, "You'll have to try it and see what it does", questions.

 

It will double the confinement provided by the first layer, and if that first layer isn't QUITE strong enough then a second may just do the trick. But it may also be too much.

 

Getting the pasting (and/or spiking) "just right" for best burst effect, without pulverizing the contents, is really an art. I'm still learning.

[ST1DinOH]

I think that's one of those, "You'll have to try it and see what it does", questions.

 

It will double the confinement provided by the first layer, and if that first layer isn't QUITE strong enough then a second may just do the trick. But it may also be too much.

 

Getting the pasting (and/or spiking) "just right" for best burst effect, without pulverizing the contents, is really an art. I'm still learning.

oh

 

so it's possible to over confine them?

 

here i thought my only limitation was the ID of my HDPE

 

thats good to know.

[hst45]

Dude, I know the feeling! My first shells looked like Ralph Wiggum on a bad day (Simpsons reference).

 

Try cutting your pasting strips in the shape of a football, that will make them lay flatter. Then paste a layer, let the glue set for a minute or so to soften the paper, and you can press the high spots flat and then paste another layer.

[TheSidewinder]

Yeah, it's possible to over-confine.

 

2(?) years ago a club member did it with a small batch of shells he wanted to break hard, so he over-wrapped them and used a slightly hotter burst (a little whistle mix sprinkled in with his BP on hulls I think), but he said only boosted it a tiny bit.

 

Anyway, they broke like black powder salutes. One huge boom and a reddish-yellow flash. We suspect the stars inside were just pulverized and added to the bang. If there were any unbroken ones, they were blown blind. His next batch worked perfectly, IIRC.

[ST1DinOH]

Yeah, it's possible to over-confine.

 

2(?) years ago a club member did it with a small batch of shells he wanted to break hard, so he over-wrapped them and used a slightly hotter burst (a little whistle mix sprinkled in with his BP on hulls I think), but he said only boosted it a tiny bit.

 

Anyway, they broke like black powder salutes. One huge boom and a reddish-yellow flash. We suspect the stars inside were just pulverized and added to the bang. If there were any unbroken ones, they were blown blind. His next batch worked perfectly, IIRC.

well last night i taped the hell out of the 3 inch shell i made with thoes buzzballs in them. i went with 3 layers, the first one verticaly "north" and "south", then two more layers on a crossing angle. the shell looks damn good and hopefully the 3 layers of continuous tape wont over confine the shell.

 

i'm using united pyro's buzz balls as inserts. they are little flying jumping jacks that i altered by cutting the fuse very short and priming them with meal, 4f, and a pinch of dextrin. considering the fact that these aren't "stars" i hope i won't have a problem with them getting destroyed in the break. i guess if it is to confined it my blow the prime off the fuse nubs or something but i figure all 10 of thoes little inserts should catch just fine.

 

i butterflied the time fuse, and attached the lift cup only to discover that the shell is too heavy for my scale...

 

once i find a way to weigh it i'll post a pic here of my completed shell.

 

thanks for all the help and advice. i'm still waiting on a chance to fire off my 3's. i've still got 2 from a failed/scrubbed launch and now this one i made last night. i'll try and get pics of everything before hand so you guys can "rofl" at my first attempts.

[TheSidewinder]

Hmmmmm....

 

If you're using buzz balls as inserts and not stars, I think you want to do the opposite of where you're going. What you're doing comes close to a shell-of-shells. Sort of. And they're usually a soft break rather than a hard one, IIRC??

 

If those buzz balls are rock-hard and very hard to crush, it probably won't matter. But if they're relatively soft and you're spiking 3 layers, I just don't know what they'll do.

 

Make sure you get a vid of this!

[DeepOvertone]

Did this video ever happen? I've been wanting to use those things as shell inserts ever since I first saw them years ago and wonderd what they would do. I'd really like to know how they worked out.

[ST1DinOH]

Did this video ever happen? I've been wanting to use those things as shell inserts ever since I first saw them years ago and wonderd what they would do. I'd really like to know how they worked out.

yes, and it sucked

 

http://www.pyrouniverse.com/gallery2/data/500/MVI_0157.avi

 

i built this willow using the same lift, burst, ratios as the buizzball shell.

 

http://www.pyrouniverse.com/gallery2/data/500/MVI_0156.avi

 

as you can see it worked fine so i think these buzzballs are just not a good insert to use.

 

not nearly enough power in them to overcome the inital direction that the burst throws them.

 

only about 1/2 of them functioned and they weren't very impressive.

 

i was hoping for a go-getter or scrambling comet type effect but it didn't work out so great.

 

a simple BP prime over the time fuses may have been the culprit in the ones that didn't light, the ones that did were already moving so fast back to earth they just looked stupid.

[tentacles]

FrankRizzo mentioned a canister shell he did last year (4" was it?) using cheap black cat (their premium line) bottle rockets. He said the premium ones have a much brighter spark trail than the usual cheapo ones. These are the ordinary by-the-gross type rockets. Peel em off the stick, trim the fuses to a nub and dip prime a handful at a time, as I recall. Cheap and aggressive go-getters!

[DeepOvertone]

Well I'm sorely dissapointed... I sure thought that would be cool. Maybe better priming and a softer break would make it better.. Idea!!!

 

What if they were used as cores for some stars? Maybe a red star that would change to green buzzballs. Some thing that would make a good contrast. Would have to be a big shell though. Something in the 8" range to have enough of them to make it interesting.

[ST1DinOH]

Well I'm sorely dissapointed... I sure thought that would be cool. Maybe better priming and a softer break would make it better.. Idea!!!

 

What if they were used as cores for some stars? Maybe a red star that would change to green buzzballs. Some thing that would make a good contrast. Would have to be a big shell though. Something in the 8" range to have enough of them to make it interesting.

these things are just too damn small to be impressive in the air. they look cool coming off the gorund, but there just isn't enough going on with them at the altitube of a large shell.

 

even a 3 inch shell looked lame because they were so high inthe air.

 

a bigger shell will simply look worse

 

a smaller shell won't hold enough to be worth it.

[DeepOvertone]

I guess you're right... I know that we throw them in the air when we use them and they shoot them off in a random direction. But we can only get them about 20 feet up so i guess thats why they look good. Oh well, I guess I'll give up on that one.

[psyco_1322]

I shot a few with a sling shot, they get out there.

 

I heard of a guy on Passfire that makes 6in ball shells filled with the buzzballs and its amazing, he also makes mines of them by filling a 5 gallon bucket completely full.

 

The fiberglass tape if put on about 2-4 layers thick depending on the tape will be enough for the shells "pasting". I made many 3" balls this way.

 

I still have not got the ground bloomer shell tut done yet. I cant seem to find my little piece of paper with all the notes on it. Pics are all taken and I shot one test shell but I believe it to have broke too hard so Im going to try it without a booster.

[iclazion]

Hi there.

 

Okay I also pasted and made my own hemi's. I used thin crafting paper, and dextrin made with corn stach or maizena as it is called here in SA. Any way. I made a thick tooth paste consistency of the dextrin and water, and placed the strips on a peace of plastic board "to easily wash off", then using a brush i coated the one side with a thick layer.

 

Now for the trick. Rub some baby oil over the plastic ball or mold you want to use. Now take a strip and smooth it on, yes this stuff WILL get all over your hands, so stop worrying about getting dirty, there is no other way and my ball shell came out looking like a smooth, rock hard shell.

 

The trick is to smooth the paste "dextrin" hard over ontop of each strip. Let them overlap as you go along. This will take days in my case weeks. But it is well worth ALL the trouble and effort.

 

I will do a PIC - tutorial as I am starting my second shell tomorrow morning. Will keep you posted

[PoorBoy]

hey guys, figured i'd ask cause i know i'm doing it wrong. On my plastic ball shells i use pvc cement to glue them shut and i use masking tape around the entire ball, just one layer. then to fill in the gap between shell and mortar i loosely wrap it in masking paper followed by masking tape to secure it. masking paper is real thin brown paper bought at home depot in the painting section its non gummed and non adhesive. it on a roll 12" wide 100 ft long and its like $2. On my 3" shells there is like a 1/2 in gap between shell and mortar before i uglify them. I could wrap them in masking tape only for a better look but it isn't cost effective. I ordered rolls of different craft paper tape but it isn't here yet. My bp burst is fine it doesn't need any spiking or not much if any. i never tried launching a shell that didn't have the extra wrapping to fill airspace, does the airspace matter as much as i think it does? Im not wrapping for burst im doing it for more efficient lift. whats your take on this. I have heard on 8" shells a 1/2 in gap ins nothing but what about on 2 and 3. Do i need to wrap the shells for lift or is it just for burst?

[lodcomm]

hey guys, figured i'd ask cause i know i'm doing it wrong. On my plastic ball shells i use pvc cement to glue them shut and i use masking tape around the entire ball, just one layer. then to fill in the gap between shell and mortar i loosely wrap it in masking paper followed by masking tape to secure it. masking paper is real thin brown paper bought at home depot in the painting section its non gummed and non adhesive. it on a roll 12" wide 100 ft long and its like $2. On my 3" shells there is like a 1/2 in gap between shell and mortar before i uglify them. I could wrap them in masking tape only for a better look but it isn't cost effective. I ordered rolls of different craft paper tape but it isn't here yet. My bp burst is fine it doesn't need any spiking or not much if any. i never tried launching a shell that didn't have the extra wrapping to fill airspace, does the airspace matter as much as i think it does? Im not wrapping for burst im doing it for more efficient lift. whats your take on this. I have heard on 8" shells a 1/2 in gap ins nothing but what about on 2 and 3. Do i need to wrap the shells for lift or is it just for burst?

 

You are wrapping the shells for both good fit in the mortar *and* to improve both the burst strength and assist with the symmetry or "balance" of the burst and thrown stars.

 

You definitely want your 3" shells to fit right up to the sides of the mortar, it is fine if it fits in snugly, but not so tight that you have to force it down. If you try to fire a 3" shell that has 1/2" clearance you will be lucky if it goes up 5 or 6 feet. If you are happy with your three inch shells burst characteristics using minimal wrapping/spiking, and you are finding them still loose in the mortar, I would suggest trying to locate (or rolling your own) a bit smaller (inner diameter) mortar tube. Also, increasing the length of your mortar tube will assist a bit by imparting a bit more energy from the lift combustion onto a "looser" fitting shell.

 

cheers

 

-t

[Bonny]

3" shells with a QM leader should drop into a mortar easily, and not be tight...you do not need the shell to be touching the mortar walls. Mine usually have about 1/8" of clearance all the way around. IF they are too tight, flowerpotting is more likely to occur. 1/2" gap is way too much though, as noted by lodcomm.