Compressors

[Vinny]

Fellas

After some advice please. I'd like to start spray finishing some of my upcoming projects. From what i've read it seems to be another facet of woodworking that is littered with lots of opportunity to trip yourself up (something that i'm quite good at unfortunately).

Main thrust of the post is what to look for in a compressor - belt drive or direct drive, tank capacity, cfm, hp etc etc ad infinitum ?. Obviously intended use will determine a lot of factors, the plan is to use it predominantly for spraying but I don't want to preclude myself from using some air tools in the future - orbital sander and nailer spring to mind.

I've had a look at this one:

http://www.diy-compressors.com/catalog/product_info.php?cPath=28_23_53&products_id=148

which comes with optional kits

or this one:


http://www.diy-compressors.com/catalog/product_info.php?cPath=28_23_53&products_id=133

which seems to have a higher spec and is pretty much toward the top of my price range.

Are either of these suited to my envisaged needs, or should I be looking elsewhere to try and pick up a second hand model of a greater spec for the same price. I'd rather buy new as i've been stung by the dreaded e-bay in the past and it wasn't pretty, I also like the "comfort" of a warranty.

Thanks in advance

Vinny

 

[wizer]

I guess you are trying to keep your options open with going for a compressor. But you might be much better off going for a dedicated HVLP system for spraying. Compressors are big and very noisy. Do you know how much spraying you will be doing? If it's just a small amount then the small earlex unit has had good reviews. See Matt_S's thread in the Projects forum.

 

[Vinny]

Wizer. it was Matts thread that prompted my question. i've had a look at the earlex and it looks like it would be ideal for the amount of spraying that i plan to do but on the other hand its a one trick pony. As you say I'm opting for a compressor to give myself a bit more scope in the future.

 

[mailee]

Well Vinney, the more ecpensive compressor you have listed will be no good for a sander that is for sure. To use an air sander you need a lot of free air and a very large tank. It would just handle a spray gun and I mean 'just' No way would it handle a HVLP gun. Although it has 11CFM it is probably diplacement and not free delivery. What you are after would need a very large tank, belt drive, and a free delivery CFM of around 15. A compressor like this would set you back around £700 new but you may be able to pick up a good second hand one. As for a nail gun they dont need a large compressor as the air consumption is in short bursts. I have a 3HP compressor with a 50 litre tank and a free CFM of around 13 and it will just handle my HVLP gun but only just. I use an electric sander but have three nail guns I use on it from a brad nailer up to a large framing nailer. Sorry to be the bearer of bad news but better to know now than after buying one that is unsuitable. HTH. :wink:

 

[Marco]

a 3 hp compressor may be ok for feeding a spray gun (low consumption only...no sata hvlp :lol: ) and a pneumatic ros for very short periods. Most hobby compressors have a duty cycle of 50 %, this means you cant run them very long without overheating and shutt off.

If you're serious about spraying you'll need a big industrial compressor, 3 phase power 7HP minium, in that category there are only belt driven dual stage air pumps.

also you'll need dry clean air...filters...air dryers.

You may find out as many hobbyst and small workshops did, that a HVLP turbine may just be the ticket for your spray finishing.

 

[Vinny]

Mailee.

Thanks for that, probably saved me some swearing at a later date. I must admit to being a tad confused over the whole HVLP thing and a little bit "lacking" in the CFM area - before now I would have normally bought a book along the lines of "The idiots guide to spraying" and given it a good read before comitting any of my hard earned, I havn't done this time but I won't rule out the possibility.

My main confusion lies in the CFM/PSI ballpark when looking at the varying sorts of gun. HVLP - High volume low pressure ?? (please feel free to correct me if i'm wrong) I've just had a look at a couple of Sealey guns and they spec them in PSI
http://www.justoffbase.co.uk/Spray-...af74cac0a18e2dd7.e3eSbNmTb3mTe34Pa38Ta38Sbxf0

This one is specced at 15-28 psi, its also gravity fed HVLP is this different to the HVLP that you use ? The more expensive compressor that i tagged earlier says its 145psi, which before I posted this thread would have seemed to be way more than enough.

In closing the sander is not top of my list so that can be scratched off the intended use list.

Cheers again for the advice, hopefully you (or anyone else who has 2 penneth worth to offer) can clarify a bit more for me.
Apologies if this appears a bit noddy but a google didn't throw up much to lessen my confusion.

Vinny

 

[wizer]

As I said above, one big factor when buying a compressor has to be the amount of noise it generates when filling up. The bigger the compressor, the bigger the noise, generally. Although admittedly it will fill up less due to the bigger tanks. As an example, I have the 2.5ltr Axminster model and it's so noisy that I pretty much never use it. I have to wear ear defenders and if my wife or child is in the house then there's no chance. It's the biggest thug in my workshop. If you can site it outside the workshop in an insulated\covered housing, then so much the better. Think hard about how much you want to do each of the functions that a compressor can do. Nailing? Probably hardly ever. Spraying? Once in a blue moon. Sanding? Often but electric sanders are almost as good and air sanders tend not to have extraction and seem to be much more expensive to boot.

 

[Richard Findley]

Hi,

Just to add my bit - and bear in mind I'm no expert but based on experience, I have a Charnwood 3hp, 240volt, 50lt, 8 bar, 13cfm compressor which was ex-diplay and cost me £150. This works my HVLP spray gun easily, nail guns take very little air so no problem there and I use a sander which is VERY thirsty on air but never actually empties the tank (but it runs all the time!!) As previously said it is noisy but I'm in an industrial unit so again, no problem for me.

I had a few problems with the compressor, not least of which was that it was rated incorrectly (rated as 10 bar but actually was an 8 bar - they are tested to hold 50% more than rating so do the maths and try not to poo your self!!!!) but once that was sorted out it works pretty well. I wouldn't be without my compressor now, although I mat not buy a Charnwood again!!

HTH

Richard

 

[jhwbigley]

As I said above, one big factor when buying a compressor has to be the amount of noise it generates when filling up. The bigger the compressor, the bigger the noise, generally. Although admittedly it will fill up less due to the bigger tanks. As an example, I have the 2.5ltr Axminster model and it's so noisy that I pretty much never use it. I have to wear ear defenders and if my wife or child is in the house then there's no chance. It's the biggest thug in my workshop. If you can site it outside the workshop in an insulated\covered housing, then so much the better. Think hard about how much you want to do each of the functions that a compressor can do. Nailing? Probably hardly ever. Spraying? Once in a blue moon. Sanding? Often but electric sanders are almost as good and air sanders tend not to have extraction and seem to be much more expensive to boot.

Thats 'cus its direct drive, my belt driven one runs like a swish watch.

JHB

 

[mailee]

On the advert for the Sealey HVLP gun it does not state what the CFM consumption is? It makes no difference what pressure it will use in PSI as it is the volume of air that is required for a HVLP system. My gun is a cheap Silverline one and the CFM rating is 7.1. Having said this my compressor runs continuously to keep pace with it. As has been stated it may be a better option to go for a Turbine HVLP compressor and gun for your spraying. As a example I do have a Sata HVLP gun but it will not run on this compressor as it will not atomise correctlyl. That gun requires around 12CFM to operate correctly. HTH.

 

[Vinny]

Ok....thanks all for the advice, looks like in the short to mid term a turbine HVLP compressor will do what i want most of. Obviously the whole what compressor issue will have to be researched a fair bit more. So back on to the turbines...any reccomendations for turbine and gun, I've just had a quick scoot round the net and the range of equipment is quite large and the prices range is larger still, top budget for this would be 250, that should include evrything i need to get started excluding paint.

cheers

vinny

 

[BradNaylor]

I've no idea about CFM or technical stuff like that, but I do know that I do a lot of spraying, use brad nailers( :lol: ) and drills and screwdrivers. My compressor is one of these and it handles everything I throw at it.

I wouldn't go for anything smaller, though.