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Fiberglass reinforcement?
Posted: Sat Oct 18, 2008 12:05 am
by auxiliary
I am planning on building an inline advanced combustion with two 4" chambers connected with a Wye and a 45 degree elbow. The only kind of large diameter pipe available to me locally is cellular core DWV ABS and fittings. I plan on using MAPP gas in this combustion so I am worried about the integrity of the DWV ABS.
Would It be a good idea to strengthen the chambers by wrapping fiberglass cloth around all surfaces and applying polyester for several layers?
I would plan on using these supplies:
http://www.tapplastics.com/shop/product.php?pid=85&
http://www.tapplastics.com/shop/product.php?pid=35&[/b]
Posted: Sat Oct 18, 2008 12:15 am
by TurboSuper
ABS tears when it fails, so I doubt it would accomplish much safety-wise.
May as well just find some nsf-pw if you're that worried about it. I don't really see the advantage of expending all that extra time/effort to reinforce the pipe.
Posted: Sat Oct 18, 2008 1:51 am
by starman
Please don't use cellular core pipe for your chamber. Find a local commercial plumbing supply if you can't find any at Lowes or Home Depot.
The fiberglass reinforcement would help but it's a lot of trouble. Just find the right pipe.
Posted: Sat Oct 18, 2008 10:02 am
by jimmy101
If your making an "advanced combustion" then that means using the proper materials. Mickey Mousing it with fiberglass over non-rated pipe means you are making a "ghetto combustion".
It'll be cheaper, faster, safer and cleaner to just use pressure rated PVC pipe and fittings. Even if you have to order tha parts online it'll probably end up costing less than the non-rated ABS + fiberglass cloth + fiberglass resin.
Posted: Sat Oct 18, 2008 10:25 am
by auxiliary
Thanks for the advice. I guess if I'm making an advanced combustion I should be patient and order NSF-PW online. Thanks for potentially saving me some money and my face!
Posted: Sat Oct 18, 2008 11:34 am
by ALIHISGREAT
rated ABS is ideal... but i know you can't really get it in the US...
Posted: Sat Oct 18, 2008 3:46 pm
by nivekatoz
If weight is not an issue , use galvinized pipe. I think that stuff can hold up to 1000 psi, if not more ,before bursting. I was online and found a place that sold aircraft grade aluminum sch 80 . Im not sure what the grade was but,I think it was t-6 something??? I looked it up on the internet at the time and it said the tencel strength was like 10,000 psi +. Im not sure what tencel means, but it sounds strong.

Posted: Sat Oct 18, 2008 4:20 pm
by Fnord
Im not sure what tencel means, but it sounds strong.
*facepalmheaddeskcombo*
Posted: Sat Oct 18, 2008 5:00 pm
by TurboSuper
Any metal pipe in 4" dia, be it copper, steel, or aluminium, is going to cost a bloody fortune.
Posted: Sat Oct 18, 2008 7:13 pm
by starman
nivekatoz wrote:If weight is not an issue , use galvinized pipe.

galvanized pipe...did I miss something? He did say he was building a standard advanced combustion didn't he? This would be ridiculous and completely unnecessary.
Posted: Sat Oct 18, 2008 7:24 pm
by DYI
You can make some impressively strong pipe with solid-walled ABS pipe and copious amounts of glass fiber and resin. I made a barrel with it so strong that it flash-boiled on the inside, and still remained intact at a 20x oxy/propane mix with a jammed round. It's also bloody heavy, and a gigantic waste of money when it's even remotely possible to find better materials.
Posted: Sat Oct 18, 2008 11:04 pm
by D_Hall
nivekatoz wrote:If weight is not an issue , use galvinized pipe. I think that stuff can hold up to 1000 psi, if not more ,before bursting. I was online and found a place that sold aircraft grade aluminum sch 80 . Im not sure what the grade was but,I think it was t-6 something??? I looked it up on the internet at the time and it said the tencel strength was like 10,000 psi +. Im not sure what tencel means, but it sounds strong.

Dear God, I hope the above post was a joke. If it was, I appologize for being humor impared. If it wasn't, well, I feel morally obligated to hit nivekatoz with the Clue Bat....
Galvanized pipe... There are many different kinds and each kind will have a different pressure rating. You may very well have seen a piece that was good to 1,000 psi but that means exactly nothing without details and is therefore completely useless information.
With regards to aluminum, "T6" is a heat treatment process, NOT a grade of aluminum. You claim "aircraft aluminum" which can (again) mean MANY things since many different types of aluminum are used in aircraft. Still, 6061 is probably the most common aluminum alloy refered to as "aircraft aluminum". Why? Because it's about the cheapest stuff used in aircraft so if somebody has some aluminum parts that they want to advertise as if they're using super duper alloys... Well, they use 6061 T6 and call it "aircraft aluminum" like it's something special. Hint: it isn't anything special. Oh, and it's tensile strength should be on the order of 40,000 psi, not 10,000. As a matter of fact, if you find ANY "structural" materials that are rated at 10,000 psi, run away as fast as you can. I don't know what you've got your hands on, but 10,000 psi is beyond pathetic for metals.
Posted: Sat Oct 18, 2008 11:35 pm
by CasinoVanart
jimmy101 wrote:If your making an "advanced combustion" then that means using the proper materials. Mickey Mousing it with fiberglass over non-rated pipe means you are making a "ghetto combustion".
It'll be cheaper, faster, safer and cleaner to just use pressure rated PVC pipe and fittings. Even if you have to order tha parts online it'll probably end up costing less than the non-rated ABS + fiberglass cloth + fiberglass resin.
Very well said Jimmy.
Posted: Sun Oct 19, 2008 12:34 am
by Gippeto
TurboSuper wrote:Any metal pipe in 4" dia, be it copper, steel, or aluminium, is going to cost a bloody fortune.
I've been pricing out 4" pipe lately.
Even low grade steel has a tensile strength of 50 000psi +. (yes, I know that's not a burst rating, rough calculated burst pressure is around 1300psi)
I have found that 4" auger tube can be had for $6/foot.
4" galvanized exhaust pipe costs $10/foot.
Am I out to lunch thinking that is reasonable?
Posted: Sun Oct 19, 2008 2:24 am
by D_Hall
Gippeto wrote:Even low grade steel has a tensile strength of 50 000psi +.
"Mild steel" is typically A36 or very similar. It's called "A36" because it has a tensile strength of 36,000 psi. A42 is also refered to as mild steel from time to time (42,000 psi tensile, of course). But to get up to 50 ksi you're starting to get into steels that shouldn't be classifed as "low grade."
Disclaimer: I'm assuming that you're discussing yield strengths and not ultimate strengths since yield would be the value that is usable for our applications.