SpudFiles

I am currently building my first combustion cannon. I live in the UK and went to B&Q to get parts however I could only find the smaller PVC pipe and its fittings.

I am using 40mm PVC pipe for the barrel. I have constructed the gun to the point of where the combustion chamber should attach but I am stuck here.

What size combustion chamber should I use with a 40mm barrel? I was thinking 75mm but the parts are expensive for that. The threaded adapter and end cap are nearly 7 pounds each of the internet!

40mm>63mm parts seem to be cheap and readily available however will a 63mm combustion chamber be too small for a 40mm barrel? Would the power suck?

Any good sources of PVC pipe fittings in the UK? With cheap shipping? Also I assume I can get 63mm (if I need to) PVC pipe from B&Q ok?

Thanks! Sorry for so many questions I'm a newb.

Bad timing for finding UK suppliers.

I had a look at B&Q online and they're not stocking anything larger than 50mm waste pipe.

The forum that I'd normally check is down and the only one I can recall at the moment is Hendersons .

Hendersons mainly sells pressure pipe and wherever you found 63mm fittings may also have been which will certainly cost more than the low pressure rated stuff in B&Q.

However Hendersons also does waste pipe and associated fittings which are worth a look. A screwed access plug @ 50mm costs just £1.53. Shipping probably another £2.50.

For a basic combustion low pressure rated pipes and so on won't be a problem.

pipestock.com - only for large amounts but its worth putting.

colglo.co.uk - good for 3m lengths.

kiowa.com - 1m lengths under the 'pipe fittings' section.

i can recommend kiowa.com and colglo.

http://www.trssupplies.co.uk/index.php?cPath=134
and
http://www.hendersons.co.uk/Pipework2/index.html
are the two best online pipe suppliers in the UK.
I have ordered from hendersons many times and the guy is very friendly and will help you find the part you need or an alternative if one doesn't exist/isn't available.
Both are similar on price, but TRS sometimes comes out a little cheaper, sepecially if you want something non-pipe related too.
Well worth running your order through both to compare.

Edit: yeah, you may want to use kiowa to get 1m of 110mm/75mm, but if yo can find somewhere selling a short length of waste pipe with a good diameter, you can use thatfor a simple combustion.

Kiowa is expensive! 3 inch pipe costs about 20 pounds for 1 metre! My problem is that I have started in metric and all the good pipe and fittings are in imperial.

A 40mm metric to 3 inch imperial adapter is not only impossible to find but also would be very expensive.

I have a friend who works as a plumber, maybe he can help me out. Will check over the websites you suggest again

Thanks

Definately stay metric! what parts are you looking for exactly? I'm sure that between hendersons and TRS supplies you'll find it? When UKSGC is back up, check the buy/sell section there.

Consider epoxy casting as a cheap and effective substitute for standard fittings.

jimmy163 wrote:Kiowa is expensive! 3 inch pipe costs about 20 pounds for 1 metre! My problem is that I have started in metric and all the good pipe and fittings are in imperial.

A 40mm metric to 3 inch imperial adapter is not only impossible to find but also would be very expensive.

I have a friend who works as a plumber, maybe he can help me out. Will check over the websites you suggest again

Thanks

it may be bad value... but it costs less than buying 3m if you are only using 1m

I checked Hendersons and they actually have a lot of the stuff at sane prices, however I just realised my gun thus far is pressure rated ABS and not PVC as I thought.

I am using marley solvent glue which it says should be used on ABS, PVC or PVCu.

Since it is an all purpose pipe weld glue, would I be ok mixing ABS and PVC? Applying the glue properly and then taping over the joints tightly for extra support?

For a basic combustion, you probably won't need to bother with the extra tape. My first combustion which I ran on unmetered propane had a 2" ABS barrel, and a 110mm ABS chamber, with PVC fittings, and was glued with sticks like sh*t glue! (the type that comes in a mastic tube)

Ok. Think I will get ordering some parts. Since i cant get a 40mm to 75mm reducer I will need to use 2 spigot type reducers.

So I will need the following reducer spigots:

75/63 x 40mm

and

90/75 x 63mm

This plus the end caps etc comes to 20 quid inc P&P. This plus a tenner spent already, plus the 75mm pipe I need.

So much for a 20 quid spudgun project

Actually a 75/63 spigot fits around 75mm and inside a 63mm fitting, so you're fine there.
Have you checked ordering the same thing on both sites? If I remember correctly, TRS has slightly cheaper postage for just fittings, and tax is included on the stated prices.

Sorry for the little off toic quesion but: would it be worth orderign things fom UK suppliers (or other supplyers on my continent), if i live in another european country?

jackssmirkingrevenge wrote:Consider epoxy casting as a cheap and effective substitute for standard fittings.

Just while you on epoxy... is epoxy casting and epoxy resin the same or different o.O cause epoxy in Australia is like super expensive it's like 5bucks for 8mL or 13bucks for 35ml... and halve them for the resin and epoxy ... I forget what their called :*(

Hmm. TRS has the correct reducer I think. Its a 90/75 mm x 40 spigot reducer.

The diagram shows the inner of the large end as 75mm and the smaller end as 40mm.

This is correct to buy?