Jump to content


Photo
- - - - -

Screen mixing with metal in the mix


  • Please log in to reply
9 replies to this topic

#1 Uarbor

Uarbor

    Pyrotechnician

  • Full Member
  • PipPipPipPip
  • 281 posts

Posted 24 July 2022 - 07:23 PM

I am making stars with magnalium included. I have read a bunch of threads that said don't put metal through your screens. But I'm using a 40 mesh and my metal is 200 to 325 mesh. I can't imagine metal getting stuck in a 40 mesh at that size. Just figured I would touch base before I go ahead and do it. Previous to this I have been screen mixing with a frying spatter screen. The results were okay but some of my colored Stars had white spots in them when they burn. So I wanted to try to mix it better. Thanks in advance for any response.

#2 Carbon796

Carbon796

    Pyrotechnician

  • Donator
  • PipPipPipPip
  • 570 posts
  • Gender:Male
  • Location:Lake Havasu, AZ
  • Interests:Machine tools, vintage cars/hotrods, cylindershellsmuthafucka.

Posted 25 July 2022 - 10:49 AM

Thats perfectly fine and is standard practice.

Not putting metals through your screens. Really only applies to course and hard metals. Like TI & FeTi.

Fyi the "standard recommended" mixing screen mesh, for incorporating comps. Is 20 mesh, though I generally preferred a 30 mesh. A 40 mesh, may take a significant amount of effort to work the comp through.

#3 Arthur

Arthur

    Firebreather

  • HE Qualified
  • PipPipPipPipPip
  • 3,716 posts

Posted 25 July 2022 - 12:42 PM

I'd suggest that the material of the screen is important! Brass or stainless could be better than window screen.



#4 justvisiting

justvisiting

    Pyrotechnician

  • Full Member
  • PipPipPipPip
  • 441 posts

Posted 25 July 2022 - 01:03 PM

I've always followed the advice not to put metal through screens, and my stars have come out fine. Magnalium is hard and gritty. I see the possibility of it sensitizing the mix. I mix it in after screening and feel 'a bit' safer for doing so. Everybody has their own perception of risk, and our perceptions often differ :)



#5 Uarbor

Uarbor

    Pyrotechnician

  • Full Member
  • PipPipPipPip
  • 281 posts

Posted 25 July 2022 - 01:18 PM

I bought a piece of 40 mesh stainless and made my own frame from an old oak dresser drawer. I did screen it a few times through the frying spatter screen but I could still see white specks in the comp. So I just wanted to run it through a finer screen a couple times. I probably should have ran the individual chemicals through the 40 mesh first. But I never really needed to do it before except this time I purchased High Purity KP and it was kind of lumpy. I normally use KP with anti cake and it is as fine as silk. Also I did not want to get anything in the way of making the ultimate blue. It definitely made the blue comp more homogeneous it did not have any metal in it. Next comes red and it has metal which is the reason for my question in the first place.

Edited by Uarbor, 25 July 2022 - 01:22 PM.


#6 Arthur

Arthur

    Firebreather

  • HE Qualified
  • PipPipPipPipPip
  • 3,716 posts

Posted 25 July 2022 - 01:52 PM

I made successful screen sets by using a set of plastic (PP I think) kitchen storage boxes. Push a mesh into the bottom with a soldering iron than melt the bottom off with the iron, leaving the mesh as the bottom of the container. 



#7 Uarbor

Uarbor

    Pyrotechnician

  • Full Member
  • PipPipPipPip
  • 281 posts

Posted 25 July 2022 - 07:07 PM

I made successful screen sets by using a set of plastic (PP I think) kitchen storage boxes. Push a mesh into the bottom with a soldering iron than melt the bottom off with the iron, leaving the mesh as the bottom of the container. 

Nice

#8 Arthur

Arthur

    Firebreather

  • HE Qualified
  • PipPipPipPipPip
  • 3,716 posts

Posted 26 July 2022 - 02:53 PM

https://www.abprospecting.com/node/643



#9 Scotty123

Scotty123

    Playing with fire

  • Full Member
  • PipPip
  • 10 posts

Posted 22 August 2022 - 01:16 AM

I'd screen the individual chems through a finer screen first, to ensure there aren't any (durable) lumps.

Stainless screens seem less likely than brass to wear quickly or get metal particles embedded in them.

#10 Mumbles

Mumbles

    Grandmaster

  • Admin
  • PipPipPipPipPipPipPipPipPipPip
  • 11,803 posts
  • Gender:Male
  • Location:Above You

Posted 01 September 2022 - 09:56 PM

I tend use a 24 or 36 (I think) for most of my mixing.  I can't remember the exact meshes, but I got a good deal from McMaster on some slightly off-standard sizes a while ago.  I used to have a set of stackable screens, similar to what Arthur described.  They were kind of nice.  I used to stack up a couple progressively finer screens, with 60 mesh the final at the bottom.  I'd pass everything through something coarse (like 16-20 mesh) to break up clumps, then my 40ish mesh screen to further break things down and mix the components, and the 60 mesh final was really to remove some garbage that was in a few of my materials.  It was especially useful for some batches of red gum and parlon I have.  The red gum has some hard bits or rocks or bark or something in it, and the parlon has some larger chunks.  I noticed a very visible improvement in my color stars doing this.  I suspect it was the parlon, but a lot of my colored stars had this faint incandescent orange tail that I always find distracting.  Screening out the coarser material with a 60 seemed to solve it.

 

I tried it with a 100 mesh screen as well, but that was way more trouble than it was worth.  After screening out the junk, I'd pass it once or twice through the 24 or 36 mesh again for better incorporation.  


Just so you guys quit asking, here is the link to the old forum. http://www.xsorbit2....forum/index.cgi

The sky is my canvas, and I have 2,113 pounds of powdered paint in the workshop.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users