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3/4" soft copper & flare

5K views 34 replies 8 participants last post by  BO185 
#1 ·
Where might I find someone who would bend me a piece of soft 3/4" copper tube and put a flare on each end? I have the old one and the fittings.
 
#4 ·
I thought of one of those, the one on my heater is a lot longer.

It's for my compressor. It has standard single flare ends. It's almost 5' long from the compressor down and around the flywheel for cooling and then to the tank. I could buy a new one for about $75 but they don't do the loop around the flywheel anymore, it's just sort of shaped like a question mark. Mine evidently broke at one time and someone tried to bend one and didn't do so well, it's kinked in half at one point. I guess it's not really hurting the performance any (if you read that post). I'd just like it to be right. Evidently they break from vibration because the parts place I deal with said they change fittings and get a custom hydraulic hose made that lasts forever. But I don't see that doing any cooling either. Maybe I'm just being too picky?
 
#5 ·
Yes, the other day I passed a truck that had what looked like a roll of 3/4" copper tube hanging on the back, I didn't catch the name though. I'll try calling a few, see if I can remember who sold me a part for my A/C last summer. The thing is, he has to be able to put my fittings on and flare the ends. I don't have a 3/4" flaring tool! Most of the time plumbers solder the fittings but you never know.
 
#7 ·
But where do I get small quantity of soft 3/4" copper pipe?

I'm starting to picture a contraption of copper pipe and 33 angle fittings and compression fittings and what the hell may as go around the flywheel twice for more cooling and, oh my.

I think I have to hunt down a plumber HVAC guy. Just in case I have to get a flaring tool and bend this myself, will filling it with sand keep it from kinking? Of course if it's on a roll we'll try to keep the bend in it, but I'm just asking for where I'll have to straighten it out.
 
#10 ·
The one OLD hardware store around here that probably had it by the foot closed up and they re opened as an ACE in a new location. Now nothing is sold by the foot or the pound anymore. :(

But I remembered a different store way outside of town and they do have it! It's copper "refrigeration tubing" as the boy said. If we can pull it off the roll sort of keeping it rolled up I'll just need to get a 3/4" flaring tool and I'll be set.

Thanks
(I may need to paint this thing before installing the new copper, I have the original color paint and the manufacturer sent me a free set of new decals) (it will look better than my 55)
 
#12 ·
When the finned intercooler line on my compressor broke many years ago, I didn't feel like buying one either, so I just took a 25 foot roll of 1/2 inch copper tubing, and put 5/8ths compression fittings on it, and a couple adaptors. It really cools the air, especially if you blow a fan on it when working it hard.
Gas compressor Pump Compressor Machine Gas
 
#13 ·
If you don't need to bend it too tight, use something like a piece of pvc pipe or a coffee can or whatever you can find that's the radius you need.

The refrigeration place you buy the tube from may be able to bend it for you too.

I had to replace the "intercooler pipe" on my compressor last year. It was long and bent in a "W" shape plus a couple more bends. I opted to just buy one for $50 if I remember the price correctly. The original had cracked after 12 or 15 years of service. I also had to buy a big wrench for the fittings.
 
#14 ·
After looking on Amazon and then Lowes online and Ace hardware online I went to Ace for the compression fittings. They stock 5/8, then 7/8". No 3/4" ?? And the kicker, the guy says, you know, we ran into this before. So why didn't you do anything about it??????????????

I go to Lowes which I passed on the way and look. Nothing looks right and sizes stop at 1/2". What the hell, I press the little help button and a woman comes to help. I tell her I need 3/4" to 3/4" compression fittings and she says they only have them that size with one end pipe thread. I said that's what I need! They were over with the water heater stuff. 2 in a pack and under $11. I couldn't believe it. I got enough copper to make 2 loops around the flywheel instead of the one. The one bracket was made for 2 tubes so I figured why not? The copper bends way easier than I thought it would. At the store they wanted to bend it straight to measure it but I got them to let me run a tape measure along the length of it as we turned the roll. Then the dippy kid mashed the tube cutter deep into it trying to cut it. I was getting impatient with him trying to cut it and was about to grab it out of his hands and start over loosing and inch, (which I had to anyway at home), but he finally got it cut, or mashed.

I don't even know if the whole deal is worth it? Will the cooler air condense more water in the tank so there is less in the lines? I'm certain flow wise I could have used 1/2", but with 3/4" the air moves slower and has more time to cool is what I was told.

I already had the 1 1/16" wrench it takes, actually not sure what the new fittings take, but I have up to 1 1/4".

When spring comes I just may play with gluing bigger fins on the flywheel for more air.
 
#15 ·
The way I look at it is that the manufacturer thought that the intercooler pipe was necessary and should be there, but it's not quite as necessary to run the tube like they do. A tube as long or longer should do it as long as you can make it fit the surroundings.

I don't recall the size of the wrench I had to buy to deal with the compression fittings, but I think it was bigger than you mention. I have a 24" Crescent wrench which will open as far as needed, as well as a pipe wrench, but neither one had enough clearance to get on the fittings and actually swing enough to tighten or loosen.
 
#16 ·
Rick, the truth is that on their newer pumps for many years now, they shortened that pipe considerably. Just going straight from the compressor to the tank. They all do have an intercooler between the high and low pressure cylinders. Now it will have about 8' of copper after the output instead of 5'. Looking at the pipe that is on it, it must be hard copper the way it is kinked. I was thinking I'd have to pull the flywheel to do this but the way this tube bends so easy, I guess I can just "thread" it onto the crankshaft and make the bends after it's on.

I had straight 30 weight oil in it to break it in which was OK the day I put it together, but by the next day the temps dropped and it didn't start easy. Liked to trip the breaker a few times first. I drained 1/2 the oil (1q) and added 1q synthetic and once that got mixed in it starts easily in the cold (it's outside). I think it's a mix I can use safely all year round.
 
#17 ·
I guess I confused myself on the intercooler piping by not reading closely enough or by making assumptions. You are right, the intercooler pipe goes between the first and second stage, and you don't really need one between the second stage outlet and the tank.
 
#18 ·
The aftercooler isn't going to remove all the water from the air, but does help lower humidity alot. Most aftercooler radiators are options on most compressors and standard on commercial ones.

The copper lines really only work till everything gets heat soaked (pumpand tank) then they lack surface air to dissipate the heat effectively. That is why on some they attach alot of fins to them. Once the tank is hot pretty much looses effects then as you're pumping air in a hot tank. Light use and they can lower temps. Discharge air can easily be 300*+ on a two stage recpi compressor. So lowing the temp helps reduce the dewpoint, with the aftercooler, so the hotter the air the more water is suspended in it. So reduce temps 20* will reduces humidity alot. But unless you get the temps low (near freezing) there will always be water in it.


I wouldn't get caught up on alot of cooper pipe if you are using the compressor alot it will heat soak and then still have water in the system. But I am sure for your use you'll won't have much issues.

If you have something to get the temp of discharge air really low like with an refrigerated air drier the air is so cool it can't retain the water and water can be easily removed from the system. Unless you're media blasting alot I doubt you'll have issues that much. Most times inline desiccants will help more and be more affordable in most cases.

Also I would add an auto dry to bottom of tank. The more water in tank displaces air as water won't compress so 5 gals of water in a tank reduces the tank by that much volume wise, plus leads to corrosion too. Ideally you would want to aftercooler pump discarge air enough so no water ever gets into the tank any way buy unless you have it run through a air drier you'll get water in the tank.
 
#19 ·
Looks like I'm back to getting a cheap 3/4" flaring tool. The soft copper pipe I bought is type L so it's too small for the compression fittings I bought (and returned). They are for type M I believe which is almost 7/8 OD. If it was a tool I'd plan on using a lot, and on hard tubing, I'd get a good one, but for this, no. I just double checked the fittings that go on the pipe over the flare and yes they are for the type L size pipe. Amazon here I come. Hmm maybe fleabay.
 
#20 ·
By the way, as above the compression fittings were for type M tube and I had type L. I went on Ebay and bought a cheap flaring tool says for "soft" tubing, it does the small stuff and on up to 5/8" and 3/4". Also it's a swagging tool if I ever have the need. I flared one end of the copper and it seemed to work well. Didn't do both ends because I wasn't ready to bend it to shape and cut the fittings off the old tube. The tool was $20.99 with free shipping so what the heck, if I ever need any tube that size that needs flaring or swagging, I'm all set. Although I'm sort of sorry I didn't get a whole roll of 1/2" like 55 rescue dog. I know that would work much better. I'm fairly certain the 3/4 size isn't for the high flow, I think it's to slow down the flow to give it more time to cool. But that length of 1/2" would do just fine especially with a fan. I'll check the temps when I get it going, in the winter, and then when it's hot out.
 
#21 ·
I don't know how much time you have in your repair project, but when mine broke, I needed it fixed now. I know it looks like a moonshine still, but I had it up and running in like 3 hours. It's been working great for years now, and if a fitting breaks, I know I can fix it in less than an hour. On any compressor the more cool air you can keep blowing on it when using it hard the better.
 
#22 ·
I have way too much time into mine. I had just rebuilt it and for the little shop work I was doing I have a very old Sears 1HP unit that I used during the rebuild and waiting for the piston that I didn't know I'd need. (between the piston, the pin, and the rod bushing it had almost .085" play). Was loud up to 25psi but pretty quiet after that. I'm curious, with that 1/2" line, what hp or cfm is yours? IDK Maybe I'll just mount a full size window fan behind the flywheel to aid cooling the copper tube and the entire compressor? (there is no belt guard to block the air flow, (it's old))

Also curious if anyone knows how the viscosity of 30 weight conventional compressor oil compares to 30 weight pure synthetic compressor oil at 120°F? I'm trying to decide if I want to run straight synthetic in it or stick to the 50/50 mix I have in it now. With the right oil, this compressor should outlast me. Actually, even with the wrong oil it will probably outlast me. :)
 
#23 ·
The property's of the synthetic in thermal break down will be better at higher temps, this means it will handle high hear better and maintain viscosity. I wouldn’t mix as your wasting money. Run either or. I run Royal purple 100 its a sae 30 weight its spendy but change it once a year. And that in a commercial environment so tons of hrs on it.
 
#24 ·
I had straight 30 in it for break in but as soon as it turned cold it was hard to start and trust me that 30 weight got thick. I used a propane torch on the drain plug extension tube to keep it flowing to get a quart out. The 30 weight synthetic poured easy at that temp, and once the two mixed it has started easily in the cold. So I don't think it's wasting my money.

Plus they sell "all season blend" compressor oils that are synthetic blends. I really just didn't want to put all synthetic in until it got broken in some more, but I doubt it's going to any more than it is. I just got my order from amazon for the Powermate synthetic compressor oil, best bargain around from my point of view at $12 a quart so when I get a round tuit, I'll change it out again. The price of compressor oil is so overinflated, it's supposed to be mineral, or synthetic oil with no additives. So they charge you more to hold off on the additives.

Back to mixing synthetic with dino oil, I don't see anything wrong with it. After all, it cured my hard start problem in the cold. And the store shelves are lined with synthetic blend motor oils. (which really can be a rip off because the gov is very lax on how much synthetic has to be in it.)
 
#26 ·
I get your point now. It does make me wonder what kind of hone pattern they put on new engines? Is it the same as ever? Anyway, the little break in my compressor had to do has been done. I'll probably drain it and just use the 2 quarts of synthetic in it and call it a day. Maybe if I get bored this summer I'll compare the viscosity of the dino and synthetic when hot.

I don't need the heater with 50% synthetic, so I'm sure I won't with 100% synthetic, although I have two of those magnetic heaters if I needed them from previous tractors I've had.
 
#27 ·
LS is cross hatch same as sbc. I think its the blocks or liners are harder vs earlier ones. I seen LS with 100k and still have hatch. Harder block/liner makes sense. I know IH blocks are high nickel and if oil changed normally they last forever and hatch will stay in them long time.
 
#28 ·
The other half of break in is how round and straight the cylinder is, and how round and straight it is when it gets to operating temperature compared to when it was honed. With that plus modern materials no break in is required at all. That's why torque plates and circulating hot water through the block while honing helps a competition engine.
 
#30 ·
Well I honed the air compressor and at first I had read where someone preferred a dingle berry type and I didn't think much about it. Then when I gave it some thought, I thought long stones would be a hellof a lot better at getting the walls true (in one direction anyway), which it certainly did need, big time! So much that I was afraid that I was going to go too far. Did I stop and measure? No, I didn't have any specs anyway. Just made sure it was close throughout the depth of the cylinders. Maybe the ball hone could have been better for the cross hatch? But not for honing in general. Anyway, it's running like new, puts out air just a little faster than this calculator says it should. https://www.airgastech.com/resources/calculators.html
 
#35 ·
The hatch also helps oil film stay on walls as it has tiny area to sit. So as piston goes up oil sticks to bore better, so with pressure lube the oil comes from piston itself and helps with it sticking to piston walls better vs splash that a scoop is tossing oil off crank to piston/bore and walls. Pressure lube is great for commercial apps running alot with a piston. Most large units running 24/7 are rotary “roots” style more efficient and less wear on parts for 100% DC.

You’ll never have an issue so not to worry should work great.
 
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