Will it do

[Spanthefestaman]

I'm looking to replace my compressor at some point as I have a job to do and I'm not sure my current compressor is up to it.

I was looking at the silent Hyundai 50 litre 2hp compressor. Main reason is its size looks similar to mine so I can keep it in the same location and it will hopefully run a bit quieter than a traditional compressor. I only rarely use my compressor for spraying and will not really use it for air tools. I have read that it has a 11cfm / 300lpm rating. What I would like to know is will it run my spray gun which has a 9.8 cfm / 277lpm rating.

I tried to study the FAQ but i cant make much sense of it. I just want to be able to use my full size gun to do a few repairs to a car I've anks brought. Id rather replace my old tired compressor for new than buy a new spray gun to suit an old compressor.

Thanks in advance!!

 

[carbon]

It’s unlikely that the compressor will keeep up with the spraygun. The 11cfm is measured when the compressor pump is running but with the outlet venting to atmosphere and not compressing.

The spray gun may work but due to the insufficient volume of air being supplied the spray pattern and paint finish will suffer.

 

[not done it yet]

FAD for the compresor. If not, it won’t.

Pneumatic tools/equipment is often specced at the minimum air volume required. Usually new and/or under ideal conditions. Is that a maximum or minimum requirement?

Might depend on the pressure required, as to how long the air supply might last - as well as the receiver volume.

2HP will be woefully short on power, woefully short on volume. I expect the figure quoted is displacement not volume produced.

 

[Spanthefestaman]

Hyundai 50 Litre Air Compressor, 11CFM/118psi, Oil Free, Low Noise, Electric 2hp (HY27550)​

Key Features​

• Low noise air compressor.
• OIL FREE – maintenance free and no oil contamination.
• 2x Hyundai 750w (1500w combined) / 230v direct drive electric motor with UK 3-pin 13amp plug.
• 50 litre tank capacity provides an air displacement of 11CFM/ 300 litres per minute and a maximum pressure of 100psi / 7bar.
• Pressure regulator with twin pressure gauges and twin quick release ‘Euro’ type air connectors and water / condensation trap.
• Includes automatic cut out switch, safety valve and pressure regulator.
• Covered by Hyundai 2 year warranty.
• Full spares available to maintain your air compressor for years to come.

Above is spec of compressor
Below is spec of my spray gun

• Air Inlet Thread: 1/4″ Universal
• Cup Capacity: 560ml
• Weight Gun & Cup: 692g
• Air Cap: Brass
• Retaining Ring: Aluminium
• Fluid Tip: Stainless Steel
• Fluid Needle: Stainless Steel
• Air Inlet Pressure: 1.6 bar (23 psi)
• Air Consumption: only 9.8 cfm 277l/min

Personally i don't get what it all means so looking to you guys for a bit of guidance.

 

[angellonewolf]

not that know much about compressers but unless its a screw type and on a 50ltr tank i dought it will be up to any air tools

my 80lte will run a quality 1/2 inch for about 3 secconds before its dies and goes that slow you have to wait for it to build back up again but it works for taking mower blades off so its used for that but now ive got battery stuff i cant remember the last time i used it

 

[angellonewolf]

theres plenty on here that spray so sure you will get input

 

[m_c]

FAD for the compresor. If not, it won’t.

Nearly all compressor output figures are a FAD figure, it's just the tank/outlet pressure it's measured at that varies.
Good manufacturer's will give it at maximum/working pressure to give a realistic expectation allowing for pumping losses, whereas lesser manufacturers will measure it at zero pressure to ignore pumping losses at pressure and give a higher figure, but both methods are likely to use a Free Air Delivery measurement.
Even sneakier manufacturer's will quote a displacement figure, which is a pure theoretical figure giving no allowance for any pumping losses.
So although this one is rated at 11cfm, I suspect they may even be specifying a displacement figure, but realistically at working pressure, 1.5kw isn't likely to produce more than 4-6CFM at working pressure, and that's giving it the benefit of only working at 7 bar.

What does cause confusion though, is how air tool consumption is rated, and I have never seen a reliable answer.

 

[Nomad]

I asked a similar question recently https://www.mig-welding.co.uk/forum/threads/advice-wanted-novice-hvlp-spraying.133818/

Plenty of good advice, it sounds like my plan to use a 2hp won’t work, one suggestion was 2.5hp / 80 litre as a minimum for spraying.

I’m still looking at options so can’t confirm.
Hope you get fixed up, keep us updated.

 

[carbon]

50 litre tank capacity provides an air displacement of 11CFM/ 300 litres per minute and a maximum pressure of 100psi / 7bar.

The pump is the thing that provides the displacement not the receiver. If the pump provides less air volume due to losses than the spray gun requires then as my previous post the paint finish will suffer.

I’ve seen someone use two 3kw belt drive compressors to be able to use a devilbiss flg5 efficiently where one compressor wouldn’t keep up with the air volume required. Using a smaller compressor also means it will be running constantly and then exceeding the duty cycle for the pump which then shortens it’s life.

Using a compressor that provides less cfm than an impact gun requires for example will work as you can wait for the receiver to refill between attempts at removing stubborn nuts etc but it doesn’t work when using a spray gun unless you are only spraying for a couple of seconds at a time.

 

[Cobbler]

What does cause confusion though, is how air tool consumption is rated, and I have never seen a reliable answer.

when I looked into this some time ago, I discovered most air tools show an average use of 25% use 75% idle to show air consumption. This means a tool showing quoted average of 4cfm actually uses 16cfm while the trigger is pulled. This is fine for something intermittent in use, but for a sander or something that you use continuously, you will run the tank flat in no time. I got caught out with this a long time ago, I bought a 3” cut off grinder, on the box 4cfm, looked on the paperwork inside on the spec, it said 4cfm average 16 cfm continuous. With a 1.5hp compressor it was totally useless.

 

[steveo3002]

if youre looking to respray cars often then you need a HUGE compressor to cope

if its the odd panel and bumper corner then you can get by with a little one , i do odds n ends with a 25ltr aldi one , not ideal in anyway but its better than a kick up the bum

 

[Spanthefestaman]

OMG its a very confusing area to look into.
My current compressor is a very old Tiger 8/40 that a friend gave to me. I have a rubbish clarke air filter on it and different types of hoses. I did manage to use a full size FLG5 primer gun on it to prime my wifes bumper. I'd be the first to admit that it must have battered the life out of it to do it as it did pass some milky oil residue into the filter. I then cleared the tank as best I could running it to max pressure and draining the tank a few times to make sure it was as clean as possible. I then managed to paint the bumper with a Devilbiss SRi 1.2 that is rated around 3.5CFM. The result was ok, main problem being I had fast hardener and thinner and it was when the summer temps were very high.

Looking more into this I think I need to stick with my mini guns. I don't need or want to be painting in my garage too much as I still have a whole house to sort out. I've just brought a car that needs a few bits tidying up. My current Tiger compressor is a 25litre 7CFM /1.5HP, I have seen that SGS do a 25litre 9.6 CFM / 2.5HP compressor. I wonder if this with mini guns and maybe a slower hardener and thinner to give me a little more working time would do? Are you better off taking the main plug out of the tank and hard piping into that over using the supplied gauge and air fitting? I've also seen that you are better of running the regulator at around 60-70psi to help with fluctuation. I also use a gun regulator so I can keep an eye on pressures.

 

[carbon]

I don't need or want to be painting in my garage

main problem being I had fast hardener and thinner

It seems you have used 2k paints in the garage from you previous post. See this post about using 2k without an airfed mask. You will need a lot more air to be able to use a spray gun and an airfed mask to be able to safely use 2k paints.

 

[steveo3002]

if its just touch ups on your own daily drivers then id say just stuggle on with a smaller one , say like a bumper even if you do it in 2 halves while waiting for the comp to catch up , an hour with polisher will make it right , vs having bodyshop spec gear for the odd bumper corner every 6 months

 

[Spanthefestaman]

I've only ever painted 2k and never in a professional booth. We had a "spray room" at my previous work which was 10meters long for painting jumbo Transits and Movanos. There we did you air-fed mask and three stage filters. At home I've done little bits of 2k and a bumper but that was outside hence the sun cooked it alive to quick. I do wear a proper mask at home granted not air fed but capable. As you say 2k is harmful so I'm mindful of this and will only do what I think is safe.

I have a dent in a wing which I might get a dent man to sort and see if I cant paint the scratch with a brush flat back and polish. A door that needs either a mop or repaint. Same with a quarter that has lacquer peel but its the bottom only not the full quarter and around the pillar. Another quarter that is badly damaged and needs pulling and painting but only the bottom. A rear bumper repaint and the front of a sill. I will only be doing one bit at a time and not all on the same day. Will take my time so that the filler and primer doesn't shrink back, also looking to get a infra red lamp to so I need the products are cured well.

The SGS compressor is £115, so TBF if it is hammering it to death who cares you just get another. If the old Tiger took it I'm sure a nice new one will. And i already have a nice mop as I am under no illusion it will come out mint. Main thing is I don't want runs, don't mind a slightly poor gun finish that will polish but don't like runs haha

 

[ajlelectronics]

The SGS compressor is £115, so TBF if it is hammering it to death who cares you just get another.

Or get the right model the first time. Minimum of 3HP belt driven and 100l tank.

 

[Spanthefestaman]

I could get a100litre one but it would spend 95% of its time doing nothing. In a garage you are still likely to only do a reasonable paint job at best so it will need a flat and polish. To do what I need to I could do with an infra red heat lamp and a pin welder so I can pull a wheel arch. So if I can spread my budget and get what I need I would rather do that. I can make a smaller compressor work, thinner paint, slower products, use my mini gun instead of my full size gun I hoped to use. I've used worse at times.