If you are using DWV, then ABS is the better choice. The difference between schedule 40 and schedule 80 is the wall thickness of the pipe - a higher schedule number designates a higher wall thickness, and with it a higher pressure rating.

If it was slip-slip it would be called a reducing coupling or bell reducer, not a bushing.
Check out this page: http://www.flexpvc.com/cart/agora.cgi?c ... 1784.11125
Click on the 'PVC-Couples-Reducing' link. The reducer is near the bottom, product number 429-420.

One little tip about shortening the PVC valve...your valve handle, when open, now becomes a stress point and a target for damage during handling. This is true, however, I think it depends on the user. I did the same thing on my spray & pray almost a year ago and it has held up fine without incident...

Sorry for the late reply, but hopefully this will help. Here is the vent I will be using on my next combustion project. This is an NSF-PW 4" plug. It was marked SCH80 but my supplier told me that it is actually SCH40. The ball valve is a 1" PVC valve with the threads removed from one side (for low p...

Very nice with lots of features. I noticed you also used the Latke plug. That is a massive chamber; how long is the barrel you attach to it?

You might want to look into an electric BBQ lighter; I've been using them for quite awhile now and I've found them to be extremely reliable and they last a long time on a single AA battery. If that's not an option you could try the motor idea but set it up to fire remotely when a switch is pressed.

The camlock fittings I buy might have a slightly smaller inner diameter. To pass a 1.5" pipe through, I first run a 1 7/8" hole saw through and then finish it off with a dremel sanding bit. Takes me 10 minutes this way instead of an hour of doing it with the dremel only. I didn't think epoxy could s...

Just because it's grey doesn't mean that it's SCH80. My local PVC distributor offers SCH40 pipe and fittings in both white and grey. It should say SCH40 or SCH80 on it.

Such pipe is very hard to find in my area as well. However, after a few months of searching, I was finally able to track down some SDR-21. If you're in southern Ontario or the Buffalo, NY region, check out Industrial Plastics Canada. website: http://www.industrialplasticscanada.com/ They will get yo...

Wouldn't epoxy be the best thing with which to fill it? Hot glue could work but it's rather nasty and doesn't stick too well, and I've noticed that PVC cement tends to shrink when it dries.

The door is only particle board (not plywood) and has quite a few years behind it, so I would assume that a pneumatic of the same size could easily accomplish the same thing (I won't be testing this - repairing the door once is more than enough). I'm really looking forward to seeing what a 4" diamet...

About a month ago, I found two golf balls in my backyard, and they differ in diameter by about 1/8". I won't be able to test their fit in SDR-21 until next week, but I'm assuming that one of them will fit very poorly. I suppose that different manufacturers produce balls of slightly different size. T...

If you're making a combustion launcher, you should be fine. Many people have used DWV (and still do) for combustions. However, if you're planning to make a pneumatic, you should scrap both the DWV pipe and fittings (or save them for a combustion) because pressurizing that stuff is very unsafe. Don't...

The igniter is for a Centro barbeque - I got it at Canadian Tire for $15. The two sparks are created by wiring them in series, there are many resources on this site and other sites to help you figure out how to do that. The aerosol I use is an antiperspirant called 'Secret'. It packs a punch but lea...

It's good for a first effort. Extra props for the use of the BBQ igniter; I use them on my cannons and they work wonderfully.

Wouldn't a chamber fan get gummed up and not work properly after being continuously doused in hairspray?