Whistle mix slightly expands after pressing. Help!

[Gunter321]

Hello i noticed that after pressing my whistle Motors the whistle mix expands a little bit. I first noticed it becaus the end of the delay Was not flat it was the shape of a Dome its not much but you can notice it and also the motor dose not slip back on to the Spindel. So my question is, is that normal has anyone experienced the same thing and what could cause it to happen? I use potasium benzoate fuel with copper oxychloride and Vaselin.

[dagabu]

Yes, we call that the "relaxation theory" and many people have done all sorts of stuff to fight it.

 

I am using mineral oil and the baggy method. When I press my motors, I use a LOT LESS pressure than most, right around 5000 lpi. I allow several seconds of dwell time and use 1/2 ID increments.

[Gunter321]

Hello Dagabu

Thanks for the Reply. I got a couple More questions Why Are people trying to get rid of it does it increase the chance of catos?

Will tube waxing help ? And because you said that you use mineral oil I was wanting to switch to parafin wax because of the longer storage time will that make it worse?

And what do you mean with dwell time is that the time between pressing increments with the rammer out or in the tube ?

And what other things could cause the expansion to get worse, is the tube support a big reason it could be worse ?

Btw I press to 8000psi

And one more thing what are 1/2 Id increments? Is that just a increment that when pressed it’s at half the height of the tube Id ?

Sorry for my bad grammar I don’t speak English.

[Richtee]

dwell time is the amount of time you leave the pressure “on” the press. You should let the pressure remain on for some time before releasing for another addition of fuel. When making black powder I’ll let the press rest sometimes 10 mins before increasing pressure. It’s kinda amazing how much the puck “settles” and you can add more pressure fairly easily.

 

 

and yes, 1/2 ID increments means press not more than 1/2 of the tube’s diameter of fuel at a time. DIAMETER, not height. 1inch tube diameter, no more than 1/2 inch amount of fuel for each pressing.

Edited October 29, 2023 by Richtee

[dagabu]

Correct, dwell and ID are aht Richtee says they are.

 

In my making of whistle, I have found no difference in storage times as long as that specific batch is pressed correctly. I do not wax anything, even my eyebrows.

 

Yes, a tube support must be rigid or the tube will expand.

 

I use the dwell time that increment needs in order for the gauge to not decrease in pressure over time. This is MUCH easier to achieve with smaller increments.

[Gunter321]

Ok thanks for the help I really appreciate it.

 

But I got one more question it’s a a bit of topic but is it correct that strobe frequency changes with tube diameter with I smaller diameter the strobe frequency will get faster and with bigger tube diameter the frequency will be slower?