richard2

Hi

Has anyone ever tried to bind some of the more hygroscopic or even unused oxidisers using some of the more combustible resins. I know some people have been experimenting with resorcinal, does this offer enough protection from moisture to use eg Cu(NO3)2 ?

Regards



Rich

Hi

I seem to remember a post on rec.pyrotechnics by Mike Swisher regarding the use of wheat paste as a binder in compositions with fairly high levels of bright flake and also discussion of problems binding such compositions. It may be worth having a search over there.


Regards


Rich

Hi

I have used both 2 and 4 inch yellow MDPE gas pipe each with a wall thickness of around 7mm. I have never had a problem with the 2 inch even with fairly heavy cylinders and quite large amounts of lift to get them very high. However I did have a four inch fail when attempting a liquid fireball however this was probably my own fault as I added a teaspoon of flash to what was probably an already sufficient 80g of BP. The mortar was burried and no harm was done however after failure it remained in one single piece with a tear along the entire length. From this I would conclude that it is safer than the PVC as it is less likely to shatter. You will still have to do some tests with dummies to check that it is thick enough to withstand the lift of your shells.

Regards


Rich

How cautious do you go though?

It's possible to make flour explode, sugar burns. Should these then be labelled flammable in the home.

Seriously I think sometimes labelling can be a bit over the top. I'm not trying to say that if you possess anything dangerous it should not be labelled appropriately and chems should definitely always be identifiable by a label however just because it is possible to make say, charcoal burn quickly should it then be labelled flammable?

Regards


Rich

Hello

The bearings should just slide on to your rod. Have you purchased them yet? If not ask the manufacturer what tolerences they work to eg +/- 0.01mm. I use some old conveyer belt rollers with a 1/2" shaft and 1/2" pillow block bearings. These slide on and are a perfect fit however one shaft had a slight dent in it which needed some attention with a file before it would slide in. They are then secured with the grub screw built into the pillow block bearing. It is not a good idea to hammer your bearings as you may damage them. If they are a tight fit you could mount the rod in a drill and remove some material with some emery cloth.

Are you sure that the 8mm rod will be strong enough? What material is it made from? Remember it is going to support a very heavy jar full of lead.

Regards


Rich