How much distance to let Spring pressure off in a Sprnger

[TCLouis]

How far does on have to control decompression(recompression) when disassembling a spring gun.
I have a bad seal I need to replace, but have been stopped until I can build a device to control the spring to "open er up".

[RayinNH]

TC, I did my RWS 34, and seems like it was about an inch or so.

[HollowPoint]

I have a Umarex Octane and dismantling it only takes a fraction of a fraction of an inch of pressure to pull the captive-cross-pin out of its place and then proceed to carefully release the remaining pre-load tension of the spring. Mine is a Gas spring but I've taken apart break barrel air rifles with conventional coil springs in the same manner.

I made up a spring compressor from some of the metal scraps I had in my junk pile. I found out after the fact that I could have just as easily used the bar-clamp I had in my storage room. In fact, that's what I've been using any time a dismantling is in order. They sell bar-clamps at harbor freight pretty cheap. Just make sure it's an all steel clamp.

Once that initial little bit of pressure is used to remove the captive-cross-pin, the bar-clamp is loosened up slowly until the remainder of the pre-load is released from the spring. I'm sure you already know this but, if you try to remove the bar-clam off to the side immediately after pulling out that cross pin, there still enough tension left on the spring to do some real damage. Be careful. After that it should slide out pretty easily. Re-assembly is done in reverse order.

HollowPoint

[GhostHawk]

I would say 2" actually needed, any additional is "just in case"

I built one to dissemble one of those Chinese B4 spring guns. Surprisingly easy with a good tool. Easy to hurt yourself with a poor one.

[TCLouis]

Plenty of bar and pipe clamps around here, I just did not know how much distance the spring would be under heavy tension.

I was expecting 6" or more, but it sounds like it may be far less. . . . GOOD!

Down the road I plan to see if I can substitute and install one of the "gas pistons/springs"

[odfairfaxsub]

My rws 54 needed around 4 inches if remember correctly

[Black Beard]

Depends on the air gun. Most have some compression but many of the smaller capacity ones can be compressed by hand. Some mechanisms are easier than others to open up. Generally, ones which screw in breech plugs (eg HW80) are a lot easier while ones which need pins to be put in when it is under tension need a compressor. Large capacity and high velocity airguns will need a compressor.

You can make a compressor with a G clamp and some timber.

[TCLouis]

I plan on making something to relieve spring tension.

The problem is, that I have to design it to allow enough movement for the spring tension to be relieved.