Random Thread #1

[Richtee]

Yeah I'll definitely do that. Thanks very much.

 

Question: How bad of an idea is it to plug up mortars (2" and 3") with plaster of paris? I have loads of the stuff, lots of cardboard tubes, and no wooden plugs, so I figured I'd ask if it was at all feasible. Whenever I shoot, I dig my mortars into sand. And in making the plugs, I would shove nails or long staples through the cardboard tubes and then fill in the void with plaster. The nails would hold in the plaster a bit better. Your thoughts?

Perhaps embed some cloth/fiberglass cloth into it along with the spikes. Buried is good...but maybe the cloth will allow more launches. And you COULD add a latex component..like a grout additive..for "flexibility'? in the mix?

[NightHawkInLight]

Any of you ever experimented with copper(II) carbonate rather than sodium bicarb in glitters? I just saw an interesting synthesis video that got me thinking of uses:

 

I may give it a shot in D1 or Winokur 20. It should whiten up the flashes - how cool would a slight blue tint be?

[Mumbles]

I would add some bolts all the way through the tubes instead of relying on nails or screws. Nails and screws really are designed to be added after the plug (wooden) is inserted. With plaster, it could have a relatively weak hold.

 

I've never used copper carbonate in glitters, but I have used CuO. It makes for an interesting delay, very strobe-like. See Bill Fuch's Pop Glitter. Just something to be aware of, you're not going to get "pure" Copper (II) Carbonate from that method. It's going to precipitate as a basic salt with Cu(OH)2. Not a problem for what you're going to use it for, but it changes the stoichiometry of some things. Also, don't dry it on an aluminum pie pan.

[scarbelly]

Ok thanks guys. So there aren't any particular safety concerns with plaster, just the fact that it's not particularly strong? Considering it's so available, I'll probably use it then, and do like you said, mumbles, as it's relatively simple.

 

The thing i was thinking of with the nails is just that if I have multiple long nails all around, then the plaster would engulf the nails not allowing it to slide any up or down. I would sort of "ram" in the plaster to get it tightly in there. I guess bolts can only be stronger though, so no point in not using them.

[NightHawkInLight]

I asked the author of the video that very question about hydroxide contamination, he didn't think any hydroxides would be present. Since copper (II) hydroxide is also quite insoluble and not hygroscopic it doesn't matter as you said. I really don't care. If it turns out to yield an interesting effect in the proportions given for sodium bicarb, I then might work out a more stoichiometric comp.

 

If it ends up being rather useless I'll likely just decompose it to CuO. Take out a tree stump or two with a little Mg.

[Mumbles]

I was under the impression that all copper carbonates precipitate as the basic salt. Most commonly in the 1:1 ratio of CuCO3 and Cu(OH)2, though 2:1 also exists in nature. The Patent below seems to think the key is to keep the pH above 6.5 to avoid oxychloride synthesis, though you need a chloride source to do that like the waste feedstock they use. For us it wouldn't be a big deal.

 

http://www.freepatentsonline.com/4659555.html

[Ventsi]

I'm just wondering, can concrete be used for mortar plugs?

These will be buried in sand as well and when I can get a replacement for the plugs I'll take it.

I'm asking since it can withstand much higher pressures than Plaster and should hold up better.

[Gunzway]

I'm just wondering, can concrete be used for mortar plugs?

These will be buried in sand as well and when I can get a replacement for the plugs I'll take it.

I'm asking since it can withstand much higher pressures than Plaster and should hold up better.

 

I'm sure concrete would serve the purpose quite well, but I would say only for small mortars (3" and under should be great, going above might not be as practical). Larger ones I would say stick to more traditional methods. I've personally used plaster for my 2" cardboard mortars and then applied a suitable amount of hot glue to secure it onto a board of wood. Seemed to work a charm until the end of the night, I was being a bit rough with it from constantly moving it. I'll probably use a stronger adhesive next time.

[Bonny]

I'm sure concrete would serve the purpose quite well, but I would say only for small mortars (3" and under should be great, going above might not be as practical). Larger ones I would say stick to more traditional methods. I've personally used plaster for my 2" cardboard mortars and then applied a suitable amount of hot glue to secure it onto a board of wood. Seemed to work a charm until the end of the night, I was being a bit rough with it from constantly moving it. I'll probably use a stronger adhesive next time.

 

 

For small mortars as long as you have a drill press (hand drill WILL work), cut discs out of plywood with a holesaw. For 2" mortars I use two 1/2" thick plywood dics glued together.

[Richtee]

For small mortars as long as you have a drill press (hand drill WILL work), cut discs out of plywood with a holesaw. For 2" mortars I use two 1/2" thick plywood dics glued together.

 

Similar to what I used to do. TIP!:

 

Cut a "guide" hole in a 2" thick 2X6 or similar. Remove pilot bit from hole saw- place cut board over plywood, and use hole as a guide. Plywood discs, no pilot bit hole :{)

[NightHawkInLight]

Similar to what I used to do. TIP!:

 

Cut a "guide" hole in a 2" thick 2X6 or similar. Remove pilot bit from hole saw- place cut board over plywood, and use hole as a guide. Plywood discs, no pilot bit hole :{)

Good tip. I bet it helps keep the bit from seizing too. I've been clobbered in the head by the handle of a corded makita one too many times while using a hole saw between floor joists.

[Richtee]

Good tip. I bet it helps keep the bit from seizing too. I've been clobbered in the head by the handle of a corded makita one too many times while using a hole saw between floor joists.

Hole saws do require a "touch" to use. A gentle "rocking" motion will help with the binding problem. And don't try to ram it thru..it's a SAW, not a drill..let the saw do it's work.

 

And if you use a big enough board for the guide...you can stand on it, further adding to stability and saftey.

Edited January 21, 2010 by Richtee

[TheEskimo]

Blegh...failed my license test. Do a perfect parallel park, and think I'm off free. Turn signals, braking, shifting just fine...then I decide to go into the wrong end of a parking lot. I totally miss the DO NOT ENTER signs. Lol. Totally failed right there. Anyone else have any bad license test stories? And now I have to wait another 3 weeks to try again.

[Bonny]

Hole saws do require a "touch" to use. A gentle "rocking" motion will help with the binding problem. And don't try to ram it thru..it's a SAW, not a drill..let the saw do it's work.

 

And if you use a big enough board for the guide...you can stand on it, further adding to stability and saftey.

 

On small mortars (2" and less) I've made plugs with a pilot hole right through, just fill the hole with glue and add a cardboard disc or 2 on top. Works just fine.

Otherwise I take the pilot drill right out. Give it a quick shot with good pressure and then the hole is started and won't wander. The plugs will be just fine.

 

 

Blegh...failed my license test. Do a perfect parallel park, and think I'm off free. Turn signals, braking, shifting just fine...then I decide to go into the wrong end of a parking lot. I totally miss the DO NOT ENTER signs. Lol. Totally failed right there. Anyone else have any bad license test stories? And now I have to wait another 3 weeks to try again.

 

That sucks... all I can say is read those signs.You only have to pass once. I didn't do too well on my driving test...but still passed.

[TrueBluePyro]

Im told you just do eerything over the top, like look in the mirrors heaps just make sure they can see everything you do....and read the signs lol, that must of sucked.

[KruseMissile]

wear a hat, that way they know where you are looking. Dont use ur eyes either, use your neck if that makes sense.

[Ventsi]

Guys, I have gone the hole saw way, and its really a PAIN IN THE ASS. All the holes are undersized , and I can't cut fancy sized holes for the other mortars I have [2.25", 3.25" etc.] I guess I might just go with cement if I don't find a better option. The thing is that I need to plug close to 2 dozen mortars too..

 

Anywho... Is it just me or is PyroBin down? I cant access it for some reason...

[Mumbles]

Well you have to get a properly sized hole cutter. A 2" hole cutter makes a 2" diameter hole, not a 2" OD plug, You'd have to get a 2.25" hole cutter or so. You can also grind off the teeth and use it as an end disc cutter in a drill press.

[dagabu]

Well you have to get a properly sized hole cutter. A 2" hole cutter makes a 2" diameter hole, not a 2" OD plug, You'd have to get a 2.25" hole cutter or so. You can also grind off the teeth and use it as an end disc cutter in a drill press.

 

That work so sweet! Now, where to find Davey board for a fair price?

[Mumbles]

I've only seen Eric Hunkin's pictures. I still buy all of my disks until I can find a good allpax cutter. you may want to send Larry Karlmann a message. He recently got a bunch of board from somewhere. I've mainly been looking for 1/8" board. If you are content with 1/16", it is much easier to find at good prices.

 

I've heard good things about this place.

www.talasonline.com

 

I don't know what size of sheets this place has:

http://www.bookmakerscatalog.com/catalog/board/board.htm

[dagabu]

I've only seen Eric Hunkin's pictures. I still buy all of my disks until I can find a good allpax cutter. you may want to send Larry Karlmann a message. He recently got a bunch of board from somewhere. I've mainly been looking for 1/8" board. If you are content with 1/16", it is much easier to find at good prices.

 

I've heard good things about this place.

www.talasonline.com

 

I don't know what size of sheets this place has:

http://www.bookmakerscatalog.com/catalog/board/board.htm

 

Book binding is another hobby I have and TALAS is indispensable, much better to work with then anybody else. The problem is that Davey is about as cheap to produce as tagboard but almost all of it is taken for book binding and what is left gets a premium from the hobbyist.

 

We have a paper wholesaler here in the Twin Cities that had Davey but charges an exorbitant amount for it. They pay (in 2002) $300.00 a TON for it and sell it for $12.00 a sheet! That makes it half the price as TALAS.

 

BTW- I am working with a distributor for some 1/8" board. I will let you all know what price it comes in at.

 

D

 

BTW- I just use the $4.00 hole cutter I got from Harbor Freight until I can will the proper size punches from black pipe.

Edited January 22, 2010 by dagabu

[firetech]

Dave,

That hole cutter tends to tear up my chipboard 50% of the time. How do you use it?

[dagabu]

Dave,

That hole cutter tends to tear up my chipboard 50% of the time. How do you use it?

 

There are three things that you need to do to get good disks.

 

1.) Make sure the blades are exactly spaced so that they are running in the same channel. I do this by using my compass and drawing the circle I want to cut, put he board on the drill press and clamp it down, get the board right under the bit and adjust one blade at a time to make the same path by hand turning the chuck.

 

2.) Clamp the board down so it cant move.

 

3.) GO SLOW! You should just scrape through the first layer of paper then you can press harder.

[TheEskimo]

Whoopdee freakin' do...SATs tomorrow. Wish me luck. I gotta beat 1800, which is what one of my friends got. What did you guys get on them, or the equivalent in your country outside the US?

[firetech]

I took the ACT because it was better suited for me. I've got to take it again though, the first was just a practice.