Recovery wadding

[Bart]

Hi Folks,

I'm new to this game and I have a question. How much recovery wadding am I supposed to use? The directions say 3 or 4 sheets, but I wind up with singed parachutes. Are there any rules of thumb on the subject? Can too much of the stuff be used?

Thanks
Bart

 

[MarkII]

Enough to block the tube and make a good gas seal, but not so much that it jams the tube at ejection. As important as the amount is how you pack it. It should be crumpled or wadded, but not too much (not made into densely packed balls). A starting point would be to aim to make a lightly packed 1/2" to 1" plug, depending upon the tube size. But how effectively the tube is blocked is just as important. If you can blow into the tube and move the wadding deeper into it, yet you feel no air coming out of the other side, then you have nailed it.

 

[Pantherjon]

What Mark says is proper..But, there is only so much wadding in the 3 packs, so the 'proper' amount would eat thru the supply quickly..What you could do(I did) is invest 10-12 bucks and get a bale of 'blown in insulation' commonly referred to as 'dog barf'..When you do, you pretty much have a lifetimes supply of the stuff! When using it lightly tamp it in so you have about a layer as thick as the diameter of the body tube..

 

[Zeus-cat]

Make sure you use the insulation kind of dog barf. The other kind of dog barf is generally too runny, makes your rockets soggy and tends to be a little too chunky to be very effective in rockets. Don't ask how I know.

 

[MarkII]

Make sure you use the insulation kind of dog barf. The other kind of dog barf is generally too runny, makes your rockets soggy and tends to be a little too chunky to be very effective in rockets. Don't ask how I know.

Yes, but there's usually no shortage of it.

Crepe paper streamers, as discussed in another thread, can be used as recovery wadding because they are treated to be flame resistant. At around a buck or less per roll, they are also much cheaper than rocket recovery wadding.

 

[MarkII]

If only we could use cat barf, I would never have to buy another sheet of wadding!

 

[Handeman]

The dog barf is actually "Cellulose Insulation" It's just ground up paper that's treated with a fire retardent.
I like to use a single sheet of the wadding, lay it over the top of the BT, then fill it with dog barf as it goes into the BT. This make a very nice plug and seems to work quite well.

BTW If you're using dog barf in larger rockets, it is reuseable. It might be a little scorched, but if it stays in the tube, you can reuse it.

 

[Bazookadale]

Unless it's awful tight in the body tube I often wrap the folded 'chute with a single piece of estes wadding to protect it from the gas that may blow by the main wad

 

[Mark_L]

Enough to block the tube and make a good gas seal, but not so much that it jams the tube at ejection. As important as the amount is how you pack it. It should be crumpled or wadded, but not too much (not made into densely packed balls). A starting point would be to aim to make a lightly packed 1/2" to 1" plug, depending upon the tube size. But how effectively the tube is blocked is just as important. If you can blow into the tube and move the wadding deeper into it, yet you feel no air coming out of the other side, then you have nailed it.

Can you please help? Every single time I put in the wadding, there is air that gets passed it! I have tried over and over again but every single time it lets out air. How can I make sure it doesn’t let out any air?

 

[2-0turbo]

Can you please help? Every single time I put in the wadding, there is air that gets passed it! I have tried over and over again but every single time it lets out air. How can I make sure it doesn’t let out any air?

It depends on the diameter of the body tube. For an 19mm tube (same size as A-C Estes motors), they say 2-3 sheets which seems to work well. You’re going for roughly two body tube diameters of fill to give enough protection and cool off the hot gases. So on a larger diameter rocket, like a baby/big Bertha, you’ll need 7-8 sheets.

Blown insulation works well too for the bigger/MPR/HPR stuff. I don’t find it works well in the Estes stuff.

Here is the back of the “pro” package of wadding with some guidelines.

Edit: grammar.

 

[Mark_L]

It depends on the diameter of the body tube. For an 19mm tube (same size as A-C Estes motors), they say 2-3 sheets which seems to work well. You’re going for roughly two body tube diameters of fill to give enough protection and cool off the hot gases. So on a larger diameter rocket, like a baby/big Bertha, you’ll need 7-8 sheets.

Blown insulation works well too for the bigger/MPR/HPR stuff. I don’t find it works well in the Estes stuff.

Here is the back of the “pro” package of wadding with some guidelines.

Edit: grammar.

The directions say 2-3 sheets, but I even used 4 just to make sure, however, air can still get around it. I make them into loose balls and put them into the tube, like you are supposed to. I just can’t find the problem.

 

[kjhambrick]

Can you please help? Every single time I put in the wadding, there is air that gets passed it! I have tried over and over again but every single time it lets out air. How can I make sure it doesn’t let out any air?

Maybe ...

What do you mean when you say 'there is air that gets past it !' ?

Are you melting your 'chutes ?

-- kjh

 

[Handeman]

Can you please help? Every single time I put in the wadding, there is air that gets passed it! I have tried over and over again but every single time it lets out air. How can I make sure it doesn’t let out any air?

You can't. You can't get and don't want an air tight fit in your rocket. Ejection gases are just like the air, they flow through and around things. The ejection gases and the air inside your rocket need to pressurize to push the nose cone off. Your wading only has to protect the chute so hot gases don't reach and melt or damage the chute.

Is that actually the problem, you are melting or damaging the chutes?