DIY - Fix leaking GBB mags. (with pictures - 56k beware!)

[Amos]

Originally Posted by coachster

essentially yes. it's basically a soft silicon so you can pull it apart if required for further maintenance. It just may take a little effort. I would guess you can also remove the flow/output valve on some mags and insert a probe to assist pushing it out. but considering how it cured in the nozzle/tip, it's fairly easy to remove. it pretty much fills all the gaps where gas can leak out.

The mags that I have repaired were chronic leakers and were pretty much sitting for the past couple years.

Real easy way to pop the plates off once their sealed is to take out the pins... And gas it up

[coach]

Originally Posted by Amos

Real easy way to pop the plates off once their sealed is to take out the pins... And gas it up

true. that could work very well indeed but it could possibly lead to a second mortar incident. at least it's not a 40mm nade, full of bb's, gassed and cooked to 900psi right Duckman? bwahahaha!

[Duckman]

nonono...the nades werent cooking. the 20oz tank was cooked to that when i filled the nades

[CDN_Stalker]

Good job Coachster, real useful thread for the community.

One way I (accidentally, I didn't empty all the gas) found works to get the base out of the mag is to empty the mag of gas, put a little spurt of gas in the mag, then push the pins out. The base will pop out (put thumb over the top of it, it may pop out halfway, or more) allowing you to remove it easily. And as was asked, the seal is a medium soft silicon rubber so there shouldn't be any problem with breaking that seal to get the base off again.

Hehe, just saw Amos post about gassing the mag up to get the base out, I didn't read page 2.

[jordan7831]

Thanks for that tip, I was wondering how the hell I would pop the base plate off the damn thing.

[CDN_Stalker]

Was funny, I figured out a way (before I found out about the gas pressure popping trick) to get the plate off, will end up working well if the mag base plate is stuck on to the point the gas trick won't work. Remove the fill valve, and use a drywall expansion plug. I forget the colour, is the medium or large size, but they are the plastic plugs you use to hang a picture or mount a coat rack to a wall (drill the hole, hammer in the plug, tightening the screw causes the two halves to expand, firmly holding the plug into the wall). Anyways, use one of those, put in fill valve hole, tighten screw a bit to expand the plug, then remove the base. Remove the screw and pull the plug out after.

Incidentally, the big yellow ones work perfectly to remove those tubular locks that cable companies use to block off the cable connection in the cable boxes for TV signals. I only know this because I worked for Rogers for a bit, and if I didn't have the unlocking tool handy, I'd use the expansion plug to grip the inner core to unscrew it. Hence my getting the idea for removing the mag base.

[Long_Bong]

Great post,

Just finished doing mine,

Also added some teflon tape on my valve after a silicon bath.

Thanks Coachster

[aznpos531]

Done my leaky KJ M9 mag for about a week and couple days now and it seems to be working quite nicely
Can someone remind me why there's cardboard in my mags?

[Silverthorn]

Damn this awesome technique isn't a sticky yet?

[DonP]

I did some gasket maker work and testing recently (with exactly the blue gunk used in this thread.) Among using it for its intended purpose (making a gasket) I also used it on a leaking GBB magazine, but periodically ripped it apart at different times to investigate how it was going. Yes, this meant I had to do and re-do it many times over but I discovered something important.

Short version:

You need more than 24 hours for the gasket maker to fully cure inside a magazine.

24 hours? Sure, if what you applied is sitting in "open air". When it's inside a GBB magazine it took at least a week (at 18-20C) to fully cure! (Edit: The label on the tube says 24 hours, that's where the number comes from.)

My hypothesis is that oxygen is what's curing it, and when it's in the open air there is plenty to go around and lots of surface area. But as soon as you put it in an enclosed space (like inside a magazine) and pinch it between metal there is no longer much oxygen OR surface area and it cures... but very slowly.

Up to about a week in, the gasket maker gunk -- when used as directed in this thread -- was NOT fully cured. 24 hours was not nearly enough. (My chilly basement probably contributed though.)

The process shown in this thread is awesome. It's a great fix. Far better than anything else I've used over the years. But if you leave your mags for only 24 hours, it is not enough to fully cure inside a magazine.

[StrikeFreedom]

So the bottom is the only place for leaks? How about the top? Will glue gun work? lol

How long should a magazine hold the charge for? Because I left mine charged for 1 day, then it no more than 5 shots. I tried submerging it in water, but I don't see it leaking noticeably. There was only ONE bubble at the top hole, but it wasn't constantly leaking or anything.

[coach]

Originally Posted by DonP

I did some gasket maker work and testing recently (with exactly the blue gunk used in this thread.) Among using it for its intended purpose (making a gasket) I also used it on a leaking GBB magazine, but periodically ripped it apart at different times to investigate how it was going. Yes, this meant I had to do and re-do it many times over but I discovered something important.

Short version:

You need more than 24 hours for the gasket maker to fully cure inside a magazine.

24 hours? Sure, if what you applied is sitting in "open air". When it's inside a GBB magazine it took at least a week (at 18-20C) to fully cure!

My hypothesis is that oxygen is what's curing it, and when it's in the open air there is plenty to go around and lots of surface area. But as soon as you put it in an enclosed space (like inside a magazine) and pinch it between metal there is no longer much oxygen OR surface area and it cures... but very slowly.

Up to about a week in, the gasket maker gunk -- when used as directed in this thread -- was NOT fully cured. 24 hours was not nearly enough. (My chilly basement probably contributed though.)

The process shown in this thread is awesome. It's a great fix. Far better than anything else I've used over the years. But if you leave your mags for only 24 hours, it is not enough to fully cure inside a magazine.

Hey Don. Ya I did this back in August. It was significantly warmer back then.

[coach]

Originally Posted by StrikeFreedom

So the bottom is the only place for leaks? How about the top? Will glue gun work? lol

How long should a magazine hold the charge for? Because I left mine charged for 1 day, then it no more than 5 shots. I tried submerging it in water, but I don't see it leaking noticeably. There was only ONE bubble at the top hole, but it wasn't constantly leaking or anything.

typically leaks from the bottom but depends on brand/type of mag.

yes it can leak out the top but this fix won't help there.

no. glue gun glue won't work.

my mags can hold a charge for several weeks and even months.

fill the gun and then submerge it in warm water to allow the propane to expand more. you should find the leak. otherwise, you're filling it wrong and not getting enough gas into the mag.

[Rookie Ab]

What if you take out the fill valve ,after you check for a leak.This would let some (a little) air in, to help cure the silicone. Just a thought.

[13Fido13]

The extra air from taking the fill valve out would help, but to be safe you should leave it for a week or so.

It's better to wait a bit longer then have to do it twice and wait the extra time.