Thinking of buying my lovely wife a Hypertherm 600 for Mother's day (he he :grinpimp: )

Am wondering if a plasma cutter cuts dirty / rusty / painted steel well - or must I keep the gas axe full for that?

What are your experiences/

Thanks

I have not had a problem as long as i could get a good ground, and the pilot arc would light.
never tried cutting heavily painted stuff.
i know cutting heavy rusted stuff with a gas axe is not fun.

The only time I have had problems was with bondo, and only after it got thicker than the steel I was cutting. But that was with a very small esab 110v suitcase style plasma.

Except getting a decent ground, no problem with a dissection-extraction operation cutting through the paint and rust of the door on one of my IH rigs which have rusted body panels listed as standard equipment on the factory lineset tickets... :D

Oh yea, ESAB PCM-875 was the unit used for the surgery.

D.

I have that Hypertherm and goes trough rust-dust like a hot knife on butter :D

You will love it...

Looking fwd your article on it so I can finally learn how to use the damn thing :beer:

my hypertherm 350 hasnt had any problems with thick paint or rust.

Thanks guys, that's just what I was hoping to hear!

'nuther question though - what are you using to dry your air?

I have one of those pipe-style dryers that uses desicant pellets. Basically it's a pipe full of pellets, air comes in at the bottom and then out at the top. To be honest, I've never felt it was all that great as it always seems the sand-blaster would still clog. I'm not sure what other options there are though - it seems a commercial dryer, like body-shop would use, is hugely expensive.

??

from what i've heard, this unit isn't too bad. for $300 i'd surely try it.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=40211

the industrial units that i have installed on some of my jobs are super expensive.

most of the nicer (ie: more expensive) dryers are made for 100% duty, used in 24hr bus repair shops, train repair shops, etc etc. one of the features that makes these expensive is the addition of an electric reheat coil, which helps to avoid sweating. i wouldn't worry too much about that in a home shop because you aren't using that much volume. but in a big shop with high cfm consumption its a pretty big deal.

all it is in an air conditioner :D id say go with a cheap refrigerated unit and you cant go wrong. no need for the bling reheat units.

i would say search, but it sucks for 3 letter words like "dry air", but i know that this has come up a number of times. :D

http://www.pirate4x4.com/forum/showthread.php?t=347747
http://www.pirate4x4.com/forum/showthread.php?t=342574

just page back through this forum. there is one rather large thread about shop air, but i went back 6-7 pages and didnt see it. its there somewhere.

my 600 cuts through rust paint and light mud fine but the cleaner the metal the better the cut

Thanks guys, that's just what I was hoping to hear!

'nuther question though - what are you using to dry your air?

I have one of those pipe-style dryers that uses desicant pellets. Basically it's a pipe full of pellets, air comes in at the bottom and then out at the top. To be honest, I've never felt it was all that great as it always seems the sand-blaster would still clog. I'm not sure what other options there are though - it seems a commercial dryer, like body-shop would use, is hugely expensive.

??

Hey, the Hypertherm 600 cuts through rust, paint, etc just fine... I recently purchase dit and have cut through factory paint with more paint on top and also heavily rusted farm parts with no problem at all.

As far as keeping the air dry, someone linked to one of my threads I started regarding the same topic. From what I`ve learned in that post and from talking to other shops you MUST use metal piping, and have risers. TP Tools & Equipment has the diagram posted here, and sells "kits" for keeping your air dry... I`m doing a write-up of my "keep air dry buildup", and in the future plan to sell a kit that's hopefully cheaper than TP's Kit for keeping air dry.

Remember when building your air system don't use galvenized as it may flake over time clogging a filter.

What I`m doing personaly is using an 8ft riser 8ft sideways 4ft down + 8" down to drain, then left 8" up from drain, and up 8", then left to the filters. I`ll have pictures soon, I just need to go get some more pipe and fittings.

As far as filters go.. I`m going with the
.05 Micron From home Depot then a regulator, then the desicant pellet filter I posted in my other thread that's "4200cf", and then to the backyard and front of garage (with more risers and drains). I have a mini desicant filter on the plasma as well for any "liquid" that may have slipped by.

Making sure the air is dry is not cheap at all if you want it VERY dry. The desicant filter I`m ordering is $100 but should last atleast a year if the metal pipe and .05 micron/water/oil trap is working. You can also take the desicant pellets out and "heat dry" them in the oven according to another post in my thread which is a great option. Another option that's slightly cheaper is the LARGE motorguard filter, the extra filters are onyl $7 and you can dry them outside even,.. it runs $65 - $90 depending where you buy it. If you plan on painting I suggest you make it as dry as possible.

I haven't heard any reviews on the HF dryer but it may work now but in 3 years will it continue to work? I think for most of us a good routed pipe system and the desicant pellet dryer will work a long long time, and we wont need to store that big unit, and use more power :)

My write-up will be coming soon, and will have pictures (Just got the Digital Rebel XT) :)

-Todd

todd-

i do agree with your post. most people dont need a refrigerated air dryer.

but if you want it super dry it really is the only option. spending a few hundred on that setup versus a couple of hundred on another setup will offer a lot more protection for not much more $$$, and there aren't any consumables to deal with, and it's virtually maintenance free.

that unit is basically a cheap window unit air conditioner - i dont think quality would be an issue with the HF unit, but for a few bones you can get the warranty. really thats only a good option if you have a store that stocks them close by.

what i'd like to see (and have considered doing myself) is a homebrew refrigerated air dryer that uses a cheapo window unit you can pick up at brandsmart. the concept is pretty simple, so its probably not all that hard to do. maybe it could run double duty to cool the shop as well?

i think its a toss up, but i plan on going with a refrigerated unit as soon as i move.

What about putting the dryer in your shop refrigerator?

Seems as though plumbing it into the fridge shouldn't be too difficult.

or run it into the kitchen fridge, since you are buying this for your wife. :D

I spoke with an engineer at Hypertherm a couple of months ago on this and he stated a referigerated dryer is not needed, but recommended 2 of the "toilet paper roll" style dryers inline.

You know, I've read that too and I'm not sure how much I agree with it... if you use black pipe, the inside of the pipe will rust and then the rust and scale will flake off... so either way, crap will be flaking off the inside of the pipe. It's the same arguement people give with turbo headers not getting coated... no matter what you do, if it is mild steel... stuff will be flaking off the inside of the pipes.

Remember when building your air system don't use galvenized as it may flake over time clogging a filter.

My miller cuts through everything with ease except Powder Coating, tends to spit and sputter some.


Good ground is key !


AW

You know, I've read that too and I'm not sure how much I agree with it... if you use black pipe, the inside of the pipe will rust and then the rust and scale will flake off... so either way, crap will be flaking off the inside of the pipe. It's the same arguement people give with turbo headers not getting coated... no matter what you do, if it is mild steel... stuff will be flaking off the inside of the pipes.


No other opinions on this? I was over at a site today that had a $100K+ Air Compressor Distribution Setup that was built off of engineered drawings and spec and installed by a Union Mechanical Contractor... took note of their material selection. They used Copper Pipe for all of the bulk runs. Each station was terminated with a sweat x NPT fitting and from there all pipe was threaded Galvanized Piping with Maleable Galvanized fittings. With it only being short nipples of Galvanized pipe I don't know if that translates to it being safe to use longer runs of Galvanized pipe for the bulk runs.... Anybody with any better info? I'm getting ready to plumb my setup and I was going to use 1" galvanized because I have a shitload of it sitting around.

I think I've seen just about every form of air delivery both in the "never to use" category as well as "used for twenty years with no problems" category.

Personally, the only one that I'd never consider is PVC. I know a lot of people use it, but I have seen first hand the shrapnel that results when it does fail. Black pipe, galvanized, copper, aluminum, whatever you want -- when it fails at worst you will rupture the pipe but the pipe stays there. The PVC failure that I saw had plastic shards embedded in wood and drywall all over the place. If anyone had been standing there they would have been hurting pretty bad.

I've talked to people that don't recommend black pipe because the eventual rust will clog things up and I've talked to people that don't recommend galvanized because it will flake off and clog things up. Some sources don't recommend copper, but are not as clear why. A few have speculated that it has less thermal mass so it does not drop the condensate out as well. Others say that it is too "soft" but I'm not sure if they mean that it is a pressure issue or a susceptibility to damage issue.

Here is a page with pressure ratings on copper piping. So I think that I'd trust it on that end. Copper Tube and Fittings (http://www.coppercanada.ca/publications/pub28E/28e-publicationptb6.html) I'd recommend at least the type L copper pipe. Even though type M will give you the pressure ratings in most cases, it still is pretty thin. Type M is only for residential water supply, you aren't even allowed to use it in commercial water supply. So since you are dealing with higher pressures in air piping than water supply, I'd feel better about using the type L. Going to type K might be overkill, but the thicker pipe would give you even more protection from any abuse and possibly the extra thermal mass would help with the condensate issues.

And if they mean that it is more prone to rupture than iron pipe, there is this product which is aluminum: Garage-Pak (http://www.garage-pak.com/) I admit that does look nice, but pretty darn expensive.

My setup is copper and it seems to work well for me. Sweating pipes isn't a problem for me and black pipe or galvanized either meant buying everything all ready threaded (which would have been a hassle trying to figure out all the lengths I needed and quite a bit more expensive) or renting a pipe threader (which would be a hassle to add on or change the system).

Just my thoughts...

No other opinions on this? I was over at a site today that had a $100K+ Air Compressor Distribution Setup that was built off of engineered drawings and spec and installed by a Union Mechanical Contractor... took note of their material selection. They used Copper Pipe for all of the bulk runs. Each station was terminated with a sweat x NPT fitting and from there all pipe was threaded Galvanized Piping with Maleable Galvanized fittings. With it only being short nipples of Galvanized pipe I don't know if that translates to it being safe to use longer runs of Galvanized pipe for the bulk runs.... Anybody with any better info? I'm getting ready to plumb my setup and I was going to use 1" galvanized because I have a shitload of it sitting around.

i dont think its a problem if you filter the air at the outlets *and* its dry air.

a couple of projects ago i managed the install of an extensive compressed air and breathing air system for a train maintenance facility for our local transit authority.

the BA system was stainless, but the rest of the system as sch40 socket weld black pipe.

the system incorporated 2 super-bling refrigerated dryers with reheat, and thats what keeps the pipe nice n dry.

even if you use galvanized, significant moisture in the pipe will lead to flaking and corrosion.

go ahead and use the galv, for a home shop setup it will be fine. put a filter on each outlet.

fwiw, i used copper for my setup, but wouldn't have unless i hadnt gotten it for free :D

I used 70% GALV. and 30% black pipe.. it's what they had at the store and I didn't want to drive around... :flipoff2:

I`m testing with a smal desciant filter before I buy the larger one to see if the pipe really does help that much more.

I can't find the popular MotorGuard filters locally (or even in the province) so for now I'm using a coallescing type trap/filter on the inlet to a large desicant dryer, which has a second coallescing filter on the outlet.

The key was definatly moving the whole shebang much further away from the compressor though. I used to have just a coallescing type on the outley of the compressor, and on a humid day it would be half full after a days work. Now I get no detectable moisture from either on the other side of the shop.

For now, my line is a booty-fab nightmare of strung together hoses because the shop isn't finished, and I'm not set on positions of things yet - so I've got no drains in the lines and probably hoses filling with water - but even so, adding 30-40 feet of hose between the comp and desicant dryer made a huge difference (I went up, acrossthe ceiling, and back down for now).

XJGPN - I'm curious about the concerns with galv flakinf in the presence of moisture. Isn't that somewhat the point of galvanizing> Perhaps it has something to do with the quality of the galvenizing? Seems a strange concern to me - and i can;t see how it could be worse than black pipe corrosion. If you have lots iof galv, and can join it readly, I see no reason not to use it.

As someone said - it seems many things can work wel, and good filters are a must.

Oh yea - the Hypertherm KICKS ASS!!!!!

XJGPN - I'm curious about the concerns with galv flakinf in the presence of moisture. Isn't that somewhat the point of galvanizing> Perhaps it has something to do with the quality of the galvenizing? Seems a strange concern to me - and i can;t see how it could be worse than black pipe corrosion. If you have lots iof galv, and can join it readly, I see no reason not to use it.

I've read it on a page that advertises their setup that uses black pipe... I've noticed that galvanizing tends to flake a bit at the ends where it is cut and either threaded or grooved... I don't know how much happens in the middle of the pipe, never checked . I work in the Fire Suppression field, and I can tell you that in dry systems, which are pressurized with air, the amount of scale and rust that builds up on the inside of black pipe is sufficient that we compensate with a higher coefficient of friction than we would if the pipe was galvanized. For this reason I always use galvanized pipe when doing any type of dry system. I have witnessed first hand just how much sediment builds up within black pipe on Dry systems by watching old dry systems of black pipe that were demo'd. Not sure how positively that translates to air distribution setups since dry systems do periodically have water flowed through them, so presumably there is more moisture present throughout, but that is my experience. FWIW

Am wondering if a plasma cutter cuts dirty / rusty / painted steel well - or must I keep the gas axe full for that?
What are your experiences/


Are you thinking about getting rid of the gas axe when you get the plasma?

Rubber coating is THE WORST to cut thru. catches fire, stinks, makes shitty cuts. Other than that I have no problems

Jon

I have a TD CutMaster 38 with a Motorgaurd M26 (toilet paper filter) mounted to the case. I don't have shop air so I just hook my portable compressor direct to it whereever I happen to be working and it does a great job when the filter is properly maintained (swapped out). Of course I blow my compressor down after every use but I have no other type of filter and as long as the filter is good, it works really well. I think with the way mines set up and used my filter life is a bit short but I'm more worried bout having good clean dry air than I am replacing a filter a little early.

I also have a TD PakMaster 25 but it has the TD filter on it. It also does a great job but I prefer the capacity and filter size of the M26 just for peace of mind sakes.

I've never had any problems blowing through dirty,rusted, or oily metal but like other have said, the cleaner the metal the better the cut. I will second the comment on cutting through rubber (plastic, ruberized undercoating, Line X, Herculiner, Rhinoliner, Speedliner, ect. ect. ect.) It catches fire, makes shitty cuts, and depending on what it is (lineX is the worst so far) the fumes will stright up send ya spinnin' in a hurry.

If I was to install shop air I would use copper. Probably K hard. Black pipe rusts considerably when any moisture and air is present. My experience with galvanized is that it flakes a little no matter what. The higher velocity the media, the more it'll flake. It also flakes more in the colder weather.The reason I say this is a friend had an air system all done in galv. pipe. Every weekend he's blow it down at the tank and depressurize the system. Once winter came and it was freezing every night, he started to see gobs of galv. flakes in the filters. The only thing we could think of was the moisture was getting caught under the flakes and then freezing. Since water "grows" when frozen, it'd chip flakes off come monday when he turned the shop heat back on and pressurzed the system. He talked about goin' to copper but I guess after a couple winters everything that was goina flake off flaked off as that has considerebly slowed over the last 3 years.