Estes Engine Plugs

As I pack my stuff for my 2nd ever rocket launch I've found I've got a lot more motors than I have those little plastic plugs that keep the ignitors in the motors. I'm talking about Estes motors in the B,C and D sizes. Is there anything else I can use besides the plugs that came with the motors that would work in a pinch. Thanks

The goal is simply to keep the igniter in the nozzle and pressed against the propellant and get expelled on ignition. I wouldn't use something like masking tape, which may catch on fire and burn your bird. You might try experimenting with non-flammable substances like putty. Just make sure it will be expelled, and not clog the nozzle and force the explosion upward into the airframe.

Curious, though. They normally give you four plugs for every three motor pack. How did you run out?

But you can buy them very inexpensively. https://www.ebay.com/itm/Estes-Stan...Model_Kit_US&hash=item1c448dbac7#ht_565wt_916

I honestly don't know how I lost them .I'm sure it's just me being my disorganized self. I was thinking something like crepe paper might work but you have my thinking about maybe a drop of Play -Dough (non-flammable) Thanks for the link, I will purchase them but that won't help me tomorrow.

Use a small piece of recovery wadding rolled into a tiny ball and press in place with a pencil, pen or other. Also at most launches the used plugs are under the pads ripe for picking. Grab some and restock your range box.

roll up a tiny plug of wadding. That's how we did it in the olden days

Look around the launch pad after you launched one. The plugs are always near the pad and are reusable. I always used masking tape before the invention of the plugs. I wouldn't use any type of "putty" if you have a misfire, could be problems with your next attempts. A little piece of wadding would also work.

Masking tape works fine, and I've never seen it catch fire and burn anything, although I guess it might be possible. Just tear off a square of tape, put the igniter in so it touches the grain, bend the igniter flush with the nozzle (but don't cross the wires), place the tape over the nozzle end to hold the igniter in place. That's how we did it when I was a kid, and sometimes I still do if I don't have a plug handy.

I think I have also heard of people using a toothpick. If it is a wide nozzle, you may need to trim the pointy end a bit.

This is a club launch? There should be plenty of help and lots of spare stuff to borrow. You can probably ask around and find someone who will give you a few plugs. Iif that doesnt work, check with the folks running the launch. At my club's launches, there are little buckets next to the launch pads where you can put trash, like burnt igniter leads that are left in the launcher clips. Usually there are a few plugs in there as well after a few launches. Or just check around the pads for used plugs. They can be reused, so you might check in there.

Thanks all, I do have plenty of wadding. I'll stop stressing this . I might just be a little too excited about going to the launch

pepe said:

Thanks all, I do have plenty of wadding. I'll stop stressing this . I might just be a little too excited about going to the launch

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Nothing wrong with that! Have fun!

What are you flying?

I remember when I first started launching rockets 20+ years ago we didn't have those plugs. The instructions had you use masking tape. It worked just fine, no risk of fire. The engine just blows right through it on launch.

No need for wadding, though it might help keep the igniter pushed all the way in.

Masking tape will only catch fire if you are using a powerful battery and you short the large wires in the Estes Igniter/Starter. Those wires get very hot with large amounts of current and can set the tape strip on fire as well as any maksing tape used to retain the igniter/starter.

The plugs were invented by Estes designers after they surveyed lots of people and school teachers and other core customers for issues that needed to be addressed. One of the biggest complaints was that the solar Igniters would not ignite the motor because the masking tape method would actually pull it waway from the propellant face rather than pushing it up against the propellant face. Old-school NAR types have been using a wadding ball to retain igniters since the dawn of time - and it works great for plain nichrome wire igniters, Astron igniters (long out of production) and Solar Igniters and Starters. The plastic plugs are just a cool and simple to install solution that Estes folks created.

As mentioned, they pack extras in every pack of motors (other than the mini motors where 4 plugs match 4 motors), and are found on the ground after launch AND they sell them online if you need a lot of them.

Look at their website.

Masking tape worked OK for "Igniters" with the pyrogen tip that flares like a sparkly match head and can still work if there is a small air gap created by the masking tape pulling the igniter away from the propellant face.

Masking tape is almost guaranteed to fail with Solar Starters because the tiny wire MUST make contact with the propellant face since they do not have any pyrogen on the tip.

Mostly Custom Rocket Co. kits but we will launch a Big Bertha on a D-21, that will be my biggest motor yet .

Masking tape is your friend


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pepe said:

Mostly Custom Rocket Co. kits but we will launch a Big Bertha on a D-21, that will be my biggest motor yet .

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Sounds fun! Bertha will get quite a ride on that! Are you all set with the right igniters for the D21? They use a different style of igniter than the Estes motors do.

I got the right ignitors for the D-21s when I got the motors and have them packed together.

pepe said:

As I pack my stuff for my 2nd ever rocket launch I've found I've got a lot more motors than I have those little plastic plugs that keep the ignitors in the motors. I'm talking about Estes motors in the B,C and D sizes. Is there anything else I can use besides the plugs that came with the motors that would work in a pinch. Thanks

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Sure... you have several options... those plugs in fact are a pretty recent invention...

First, you can use those plugs over and over again... in fact, I picked up about a fistful around the pads after the last club launch, in every type and size. They may be slightly charred, but they'll work so long as they're not melted or deformed too badly to go into the nozzle. Same thing goes for wadding, by the way... I picked up a couple fistfuls off the field after the last club launch, and I stuff it in a ziplock bag in my range box... works great. Use the more perforated stuff (holes burned in it) FIRST in the tube, and then better stuff or a single new sheet above it with no holes, to make sure nothing gets to the parachute.

Second, there's the old pre-plug days standby, a piece of masking tape. That's what 95% of us used before they invented the plugs. Stick the ignitor in all the way until it's firmly touching the propellant, then bend the leads over with your finger, and slap an inch or so long piece of masking tape over it. At ignition, a hole will near-instantly be burned through the tape, no problem. Masking tape works great.

A third option is the "spitball method". Install the ignitor, then tear the corner off a sheet of wadding big enough to tightly wad up into a ball and then use a pen or pencil or bamboo skewer or whatever to cram it up into the nozzle and wedge it there to hold the ignitor in. Be sure you just don't damage the ignitor in the process... Works great and is what folks used when they didn't use masking tape, for the most part.

Another option is to use something like Quest does on the Q2G2 ignitors... a short bit of straw tubing, wedged into the nozzle to hold the ignitor in place.

You can also wedge bits of balsa, toothpics, and other stuff in the nozzle to hold the ignitor in, but the only bad thing is, sometimes flaming bits of wood or detritus used to wedge the ignitor in is expelled forcefully by the motor startup and can be ejected some distance from the pad... so be watchful for grass fires! That's why the recommendation is for either flame-resistant wadding balls (which will smolder but not burn), the plastic plugs, straws, etc. or masking tape, which will usually stay attached to the motor (but which burns through but I've never seen catch fire, because of the adhesive I suppose).

Later and good luck! OL JR

Bat-mite said:

The goal is simply to keep the igniter in the nozzle and pressed against the propellant and get expelled on ignition. I wouldn't use something like masking tape, which may catch on fire and burn your bird. You might try experimenting with non-flammable substances like putty. Just make sure it will be expelled, and not clog the nozzle and force the explosion upward into the airframe.

Curious, though. They normally give you four plugs for every three motor pack. How did you run out?

But you can buy them very inexpensively. https://www.ebay.com/itm/Estes-Stan...Model_Kit_US&hash=item1c448dbac7#ht_565wt_916

Click to expand...

Wow... NEVER heard or seen of masking tape doing anything but burning a hole in it slightly bigger than the nozzle exit... have you had masking tape catch fire and burn up the rocket?? I've NEVER seen that!

In flight the wind blowing past the rocket is SO fast that I don't see how masking tape COULD stay "caught fire"...

I've used the stuff for DECADES and never seen any such problem. Not saying it can't happen, but if anybody has ever had it happen, I'd love to know about it, because it'd be the first time I've heard of it anyway!

Later! OL JR

rcktnut said:

Look around the launch pad after you launched one. The plugs are always near the pad and are reusable. I always used masking tape before the invention of the plugs. I wouldn't use any type of "putty" if you have a misfire, could be problems with your next attempts. A little piece of wadding would also work.

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That's a good point. Putty could REALLY gum up the works if you have to install a second ignitor... I wouldn't use any crap like that either...

Later! OL JR

pepe said:

I got the right ignitors for the D-21s when I got the motors and have them packed together.

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Sounds like you are good to go!

And if anything does come up, like missing supplies or a question about how to do something you are unfamiliar with, I'm sure the club members will be happy to help. Let us know how the D21 works out with the Big Bertha. That one is going to be FAST!

I've used masking tape exclusively (I hate those plug things and just throw them out) for over 1000 Estes BP launches. I've never had any issues or have the tape catch fire. Usually there is just a small scorch burn just below the nozzle.

Read posts 11 and 12.

Oldschool77 said:

Use a small piece of recovery wadding rolled into a tiny ball and press in place with a pencil, pen or other. Also at most launches the used plugs are under the pads ripe for picking. Grab some and restock your range box.

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Before plugs, as in when I started in 1971, we used a ball of wadding shoved in with the safety key


Launching rockets (or missiles in my case) is so easy a chimp could do it. Read a step, do a step, eat a banana.

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I've used pretty much all of these methods, and they all work.

I've noticed on occasion that insertion of the poly plugs in D12 motors may cause the igniter to break. This happened to me at least twice when prepping my TLP Scud-Bs.