Injecting epoxy into a small space

I was wondering if anybody has used a particular tool or method for putting epoxy into a precise location. Specifically, I want to put a fillet of epoxy on an aft centering ring, where there's not much space between the motor tube (and retainer) and the wall of the airframe.

I have a couple of medicine dosage syringes. One of them I use for filling tube spirals, but I have a spare, and I was thinking of using that. I'm wondering if this will be a one-time use for this syringe, or if I can flush it with alcohol afterwards and use it again. Or does anybody have a means of putting a small amount of epoxy into a small space? What I have currently is Bob Smith epoxy. It's the only kind (other than J.B. Weld) that I've used. I don't know how it compares to other epoxies, but it's pretty goopy, and I have a hard time controlling it, so I don't just want to put a blob on a stick and hope it doesn't go where I don't want it.

Thanks!

THIS might be the ticket for you. I get it at Walmart but they sell through fast. It's in the hardware section. It sets in about 5 minutes and is rock hard in a little over an hour. It comes with two removable tips and mixes as you use it---upside--VERY CONVENIENT--downside--they need to give you more tips, once used they are toast. If your doing a bunch of internal fillets this should not be a problem since you'll use the better part of the epoxy at one time------hope this helps---H

I buy these things by the case at Grainger. You can get a variety of dispensing needles up to 2 inches in length in various gauges also by the case. It allows for a very controlled bead of epoxy.

https://www.grainger.com/product/GRAINGER-APPROVED-Dispensing-Syringe-WP123331/_/N-cymZ1z0odlg?s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/5FVD8_AS01?$smthumb$

lcorinth said:

I have a couple of medicine dosage syringes. ... I'm wondering if this will be a one-time use for this syringe, or if I can flush it with alcohol afterwards and use it again. Thanks!

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Yes. I can tell you from experience that it works just fine. I have a syringe that I've used and reused for injecting epoxy. Afterwards I draw up alcohol and expel it - 3 or 4 times - and it is ready for the next time.

Agree with LW Bercini. Still using the same syringe and the same container of alcohol I used on my first try a couple of years ago. Thinking about getting some new alcohol as it is getting kind of cloudy. I also use Bob Smith epoxy.

lcorinth said:

I have a couple of medicine dosage syringes. One of them I use for filling tube spirals, but I have a spare, and I was thinking of using that. I'm wondering if this will be a one-time use for this syringe, or if I can flush it with alcohol afterwards and use it again.

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Walmart pharmacies hand out baby medication syringes for free. They simply ask, "How many do you want?" To be reasonable, I say "five."

Winston said:

Walmart pharmacies hand out baby medication syringes for free. They simply ask, "How many do you want?" To be reasonable, I say "five."

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That's a good tip. I'll have to remember that next time I need to pick some up.

LW Bercini said:

Yes. I can tell you from experience that it works just fine. I have a syringe that I've used and reused for injecting epoxy. Afterwards I draw up alcohol and expel it - 3 or 4 times - and it is ready for the next time.

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I went with this option. It worked great!

+1 on syringes! Old trick: Put your part A and part B in a plastic sandwich bag and squish it around to mix it up. Cut a TINY corner off and you have the equivalent of a small icing bag. Good for getting in tight places!

Madison Alum said:

Agree with LW Bercini. Still using the same syringe and the same container of alcohol I used on my first try a couple of years ago. Thinking about getting some new alcohol as it is getting kind of cloudy. I also use Bob Smith epoxy.

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I was going to ask if the cost if the alcohol exceeded the cost of a new syringe, but now understand it's reusable too. Good to know!

soopirV said:

I was going to ask if the cost if the alcohol exceeded the cost of a new syringe, but now understand it's reusable too. Good to know!

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I think I bought a bottle of rubbing alcohol for 99 cents, perhaps a buck.99. The syringe happened to come with a prescription I got, and didn't notice until my girlfriend was throwing out the bag. She asked if I could use it for rockets (she's great!).

But the syringe I bought for spiral filling was a couple bucks - maybe 2.99, I forget. Even if I don't reuse the small amount of alcohol I use to clean the syringe (I use a couple of ounces in a Starbucks sample cup, and draw it in and plunge it out of the syringe multiple times), I get more alcohol for the price than I'd need for one application, so it works out even if I throw out the alcohol.

Winston said:

Walmart pharmacies hand out baby medication syringes for free. They simply ask, "How many do you want?" To be reasonable, I say "five."

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Asking for FIVE syringes is reasonable? I'm thinking they'll be on the phone to the DEA before I left the counter.... LOL! (But I'm gonna go try it tomorrow morning, you betcha....)

Syringes are easy to get. Needles, less so...

Marc_G said:

Syringes are easy to get. Needles, less so...

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Not true. Go to one of the Farm stores and they carry syringes with needles. I have some of the large gauge needles for jobs like this.