combustion question!

[joemama]

hello its been a long time. 4 years to be exact! well iv made 4 air cannons. and i have recently been down so i decided to make a new combustion!

To the point!

how do you get wire's inside of the gun to make a spark strip or jump. drilling? but by drilling you would have an exposed hole, it seems to me you would lose a lot of pressure. so how do you seal this hole?

thank you

good to be back

joe

[dudeman508]

Epoxy (waiting for jsr)

[inonickname]

You can tap the hole and use a threaded (conductive) connection through it such as a bolt, or use an adhesive such as epoxy, or just a silicone sealant.

[Technician1002]

How about simply making the ID of the hole the same size as the OD of the wire?

Thanks, I'll be here all week.

[jackssmirkingrevenge]

Epoxy (waiting for jsr)

I don't need to make an appearance these days thanks to my disciples

[Pookydarts]

Rubber pull-through schrader valve with the valve unscrewed and discarded, wire goes through, then fill with... you guessed it... epoxy.
Good for metal combustion chambers, and pressure rated!
Or bolt with (or without) point goes through wall, tapped or not, with a nut on each side, and filled with sealant as described by inonickname.

[jimmy101]

The usual method is to use screws.

Fine thread drywall screws work well and are self tapping. If you're using PVC or ABS then just drill a slightly undersized hole and you're good to go. Drywall screws are available up to about 3" long so you can just screw in two on opposites sides of the chamber to provide both the conductor through the cahmber wall and a nice sharp spark gap.

You can also use fine thread machine screws which will also self-tap in a suitable hole.

[mark.f]

Man... the first electrodes I installed (four years ago) were simply wood screws forced into the pipe with sheer willpower and a phillips-head screwdriver (one out of my tiny arsenal of tools back then).

If you have the tooling, I usually drill and tap holes for machine screws, and seal with either rubber washers or teflon tape.