13 replies to this topic

[Blackviper91]

Ok, so I've wanted to start modding nerf guns for awhile and I finally got around to opening up my old SuperMaxx 1500. I plugged the valve on the plunger (the 'safety' valve I assume). It took me awhile to get it plugged well, but I finally did. I started to pump up the gun, and the air tank promptly exploded. After clawing at my ears and making sure I wasn't in fact deaf (from now on I am wearing hearing protection), I looked at the damage. The flat plate of plastic where the rod connected to the valve came through had split away from the rest of the tank and cracked.

Is this common? Was my gun defective or was I just as moron? Also, any ideas on way to fix this?

Thanks for your help,
Cody

Edited by Blackviper91, 05 January 2008 - 10:07 PM.

[Forsaken angel24]

How many pumps did you give it?

[Blackviper91]

Well... I thought I had only given it one or two pumps, but I realized later that as I worked on plugging the valve, I had tested it several times and I may have pumped it 10, 20 or 30+ times. Unfortuneately I have no idea.

So is there anyway to fix this? maybe buy/trade for a new one? Also, I am wanting to modify my Titan, I assume that air tank exploding would be extremely unpleasant, any advice?

[shoeshine5]

That is just the risk you take when you plug a pump. Even the slightest over pump can destroy the gun.

[Blasphemy]

Well... I thought I had only given it one or two pumps, but I realized later that as I worked on plugging the valve, I had tested it several times and I may have pumped it 10, 20 or 30+ times. Unfortuneately I have no idea.

Well that's your problem, the SM1500's tank isn't made to take and hold that kind of pressure. With the pump plugged I would only pump it 4 times MAX. Maybe, you can repair your airtank by patching it with CPVC, it could be tricky though.

Edited by Blasphemy, 05 January 2008 - 10:54 PM.

[Blackviper91]

Ok, well, I have a second gun so I'll use that tank and be ALOT more careful. Is there a way I could make the valve stiffer but still loose enough to come open before the gun exploded?

Thanks for the help,
Cody

[Retiate]

Well, just plugging the OPRV and watching your pump number is the best way to do things. I can't think of a way to strengthen the OPRV other than cutting the pump open and replacing the OPRV spring with a stronger one.
And for SM1500's, I wouldn't go over 4 pumps, and I personally don't like to use it in the winter time. Cold temperature makes the plastic more brittle and more prone to exploding.
For the Titan, I'd go with maybe 25-27 pumps. I usually just pump it until it starts to get hard to pump.

[Blackviper91]

Thanks for all the help everyone. I'll just try to be more careful and be glad I learned my lesson, if not the easy way .

I'll see if I can repair the tank. Actually, if I use CPVC, I could probably get more pumps since it could stand up to much higher pressure.

Thanks again for all your help,
Cody

[Forsaken angel24]

Thanks for all the help everyone. I'll just try to be more careful and be glad I learned my lesson, if not the easy way .

I'll see if I can repair the tank. Actually, if I use CPVC, I could probably get more pumps since it could stand up to much higher pressure.

Thanks again for all your help,
Cody

The Cpvc can handle the pressure, but what about the seal between the cpvc and the stock plastic. Or even the valve. I would stick with 4 pumps.

[Blackviper91]

True, maybe someday I'll be really ambitious and redo the whole system. Until then, stock will have to suffice.

Thanks for the help though.

[Pineapple]

Well... I thought I had only given it one or two pumps, but I realized later that as I worked on plugging the valve, I had tested it several times and I may have pumped it 10, 20 or 30+ times. Unfortuneately I have no idea.

So is there anyway to fix this? maybe buy/trade for a new one? Also, I am wanting to modify my Titan, I assume that air tank exploding would be extremely unpleasant, any advice?

You mean you can't tell between 4 and 20-30?

C'mon.


Can you post a picture of where the damage occurred? You said it "blew out the back where the rod comes out". Is it a clean break, at a seam, or is it God-honest cracked? Mine just blew out last month when my over-excited nephew pumped it 8 times. It didn't explode, just hissed and wouldn't hold pressure... he quietly put it back in my shop (he didn't ask me if he could use it... I found out from my son that he snuck it out). But mine is cracked...no chance of a good repair since the surface is flat (as opposed to round, like the airtank body sides, in which a PVC sleeve could be used to fix it). I might try to epoxy the crack, but I'd hate to have that thing fail me during a skirmish.

I ended up using an AirTech 2000 airtank; they are EXACTLY the same size as a SM1500's airtank... except for the fact that the Liquitron power gauge is integral with the airtank, and I ended up cutting a small hole in the top of my 1500 to accommodate it rather than hacking it off and epoxying the void... the AT2000 pump is shorter than the 1500 so I kept the 1500 pump in and used the 2000's air line to tie it all together.


Four pumps is the MAX I would go with a 1500. You could squeeze maybe one or two more, but the stress you put on the plastic parts just isn't worth it. I might put a "blow away" safety valve like I did on my worn-out SM 5000 "Roadblocker" mod... simply put, a friction-fit plastic quick-connect in the air line from pump to airtank... that can "pop" off before excess overpumping would cause the airtank to crack or split. It was ghetto, but it worked, and it could still shoot 80-100 feet on four pumps with micro stefans.

Currently, my 1500/AT2k has a 4 inch PETG barrel sleeved in 1/2" PVC to a coupler on the tank. Two pumps gives 60 feet, and enough pain feedback at 25-30 feet to make it effective indoors.

Keep that second 1500 from blowing! They're good guns.


-Piney-

[Blackviper91]

Well, the reason I don't know how many pumps I gave it is because I was having trouble plugging the OPRV. I kept testing after each attempt and I apparently forgot to empty the tank in between

It did actually blow out at the seem and crack pretty seriously. I am not sure if I can repair it, but have decided I want to try redoing all the insides with CPVC so that I can pump it up even higher if it does prove unfixable. Though I think that project will come after I mod my Longshot.

I was thinking though, couldn't I get a sheet of some form of metal, cut a hole in it for the air and a hole for the rod to go through then epoxy that to it to fix the crack. Then maybe epoxy the tank back together at the seems. I'm also going to use your safety valve idea to stop me from having much chance of messing up my other tank.

Thanks again so much for all the help. I was really pleasantly surprised at how fast ya'll replied to my questions. I'll definately be staying here for awhile.

~Cody

[Blackviper91]

Sorry to double post but I just thought I'd add that I successfully integrated the good tank into my gun. I plugged the OPRV and did the BIC pen mod. It shoots really well, inside there wasn't any distance long enough for the dart to even drop from flat much.

One thing I did notice was that the unexploded tank seemed to be a slightly different design than the broken one. It was reinforced in the back where the other one exploded. The trigger also seemed to be of a slightly different, stronger, design. The guns were other-wise identical as far as I could tell and were bought at the same time so I thought this was interesting.

~Cody

[KyleDarklighter]

Well I also had my SM 5000 (small soldiers early model) tank fail as well. The shaft is no longer attached to the release valve. I'd rather not cut into it to repair it. Besides other SM or AT what other tanks are compatable?
As far as renforcing the tank there are to alternative option I can suggest trying. A product called "dipping plastic or resin" It's a type of air dry plastic liquid that objects can be dunked in to coat them in a thin layer of plastic. Also Fiberglass resin with "cheese cloth" is another method to try and strengthen the tanks.

Garrett