ShinOBIWAN said:
Ah... interesting. The hire shop I was talking to was renting out a mask and a compressor, not a bottle based system. I'll look into that.
ShinOBIWAN said:
Yea, it gets very silly very quickly when you need lots of air.
ShinOBIWAN said:
3 phase! 😱
Jeez, mate. You don't mess around do you? I thought I was pretty special rewiring the garage with a specific 20amp line for a dust extractor!
ShinOBIWAN said:
That was what I was thinking. Doing a single coat, even on a pair of large speakers isn't going to take more than a few minutes, and I'd step outside between coats (I know, possible contamination and all that) so a compressor wouldn't be running for more than a few minutes at a time.
I've mailed Devibiss about their full face unit and asked them for the skinny on compressor requirements.
TerryO said:
I think I should point out that my mail about doing mad stuff was slightly in jest. Isocyanates scare the hell out of me. To be honest, I don't really like spraying anything without the idea of breathing gear, so I'm tempted to get a setup even if I'm spraying stuff that's not so dangerous.
I do take these things very seriously. I work (hobby) with lots of MDF, which is very dangerous, so I'm quite happy to go the extra mile to make life safer, e.g. http://spikyfish.com/DustExtraction/
sploo said:
After 2 years of regular use, my poor old little 2hp 50ltr direct drive compressor has developed a metallic knock so I think the piston has some wear. I've absolutely hammered it this year though, often running it almost continuously for fairly long lengths of time whilst spraying multiple parts in one session. Priming is the killer because of all the coats, the gun I have is also 7cfm-11cfm so it wasn't ideally suited to the compressor either.
I've known I need a better compressor for about a year now but just kept putting it off but with the existing machine being on its last legs its given me the push I needed.
But selecting a replacement hasn't been easy, I've spent the entire weekend to-ing and fro-ing between choices, slowly narrowing down the selection. The good guns such as those from SATA, Optima, Iwata, Devilbiss and Sharpe are all about 10cfm+ so I knew a 3hp model wouldn't really cut it plus I wanted a large receiver tank to stop the compressor running as often. So I set a budget of £500 and quickly found that gets you virtually nothing from a dealer or online store. Looking around ebay I found the as new, 4hp, 15cfm compressor with the big 200ltr tank and went with that, it seemed like the most machine for my money without having to resort to one of the many second hand models of unknown history that litter ebay, I'm sure some are bargains but I'm also sure some are turkeys too.
Ideally I wouldn't have minded a petrol compressor to get around the 3phase issue but those models hold their price very well and many have 10hp and can easily deliver 30-40cfm(FAD). Which seemed excessive just for spraying application.
BTW I'm not doing the 3 phase install! My uncle is an industrial electrician so he'll be doing that and on the cheap too. Don't you just love skilled relatives 🙂 We have a joiner, a painter/decorator, a bricky and a kitchen fitter in the family too. No need for the yellow pages here 😀
sploo said:
WOW! Nice work on the dust collector. Mine is a 16 year old Sears shop vac.
Given the elaborate nature of your duct construction, I'd think you would have very little trouble creating a fan based air supply. 12 cfm is not a lot for a fan.
Given the right incentive (saving lots of $$$), I'm sure a design could be whipped up that will provide plenty of breatable air.
Made a compressor choice is not a easy thing due to the price of those unit and three phase issu. In france it's a big problem since those electrical installation are quite difficult nor impossible to have for home. So the other way is to find grun sprayer that need less air consuption. I chose this ONE. Look air consumption. This spray gun has a good back return on a french spraygun paint forum. I take one to go with 3 HP/100L compressor with 9.5CFM capapility at 3 bar
Marc
Marc
Idefixes said:
Hi Marc
Yes a LVLP gun or one of the mini sprayguns is a better choice for air limited users. But these are compromised compared to the full size guns. Usually they offer less atomisation of the paint and/or a small fan size. As a bonus they're often more efficient laying paint down with less overspray.
A really good gun spraying clear or base coats sprays almost smoke like material because the atomisation is that good.
As a note, if you can't get 3 phase for whatever reason then you can either chain multiple cheaper compressors together to bump up the CFM or go with a diesel/petrol model. Chaining them often works out much cheaper than buying a bigger machine but you've got the inconvenience of multiple bulky machines to accommodate and move around. There's also the issue of noise, one compressor is loud enough but two or three running simultaneously is going to probably going to start to annoy the neighbours and you.
As you've said, its rarely easy.
Ordered a new gun.
I'm at that stage where I realise, because I'm suitably enthusiastic about my finishes, spraying is now a long term thing and that I'd like to invest in a gun that reflects this. Starting out with budget but OK equipment has been a great introduction to it all though and I don't feel my existing gun has ever let me down but I do think there are better guns out there.
I looked around and poured over guns before making a decision. Initially I toyed with the idea of the SATA jet3000 digital but these are awefully expensive (about £400). I was so close to buying but had a reality check and quickly realised that I'd have to using the gun an awful lot to make it worthwhile value.
I envy the folks in the states because they have some fantastic sanely priced guns over there that we just can't get in the UK. I'd have liked if we could see the CAT Jaguar, Sharpe Razor or the Optima 900 over here. It seems if you want to buy in the UK then your limited to SATA, Devilbiss and Iwata. All make some great guns but an expanded choice would have been nicer.
After more research I really liked the sound of Iwata guns and did eventually find a UK dealer selling the top of the range W400 for £345 which wasn't far off the price of the SATA. But by a stroke of luck I found an exdisplay but unused W400 on ebay for £100. At that price I hit the buy-it-now as quick as I could.
Iwata W400
This will be my first pro level gun and I'm hoping it will enable me to take my spraying skills and finishes to the next level. I'll also have a two gun setup now where I can setup my existing Kestrel AeroFura gun with a 1.8mm tip for priming and use the Iwata 1.3mm as my base and clear gun.
I'm at that stage where I realise, because I'm suitably enthusiastic about my finishes, spraying is now a long term thing and that I'd like to invest in a gun that reflects this. Starting out with budget but OK equipment has been a great introduction to it all though and I don't feel my existing gun has ever let me down but I do think there are better guns out there.
I looked around and poured over guns before making a decision. Initially I toyed with the idea of the SATA jet3000 digital but these are awefully expensive (about £400). I was so close to buying but had a reality check and quickly realised that I'd have to using the gun an awful lot to make it worthwhile value.
I envy the folks in the states because they have some fantastic sanely priced guns over there that we just can't get in the UK. I'd have liked if we could see the CAT Jaguar, Sharpe Razor or the Optima 900 over here. It seems if you want to buy in the UK then your limited to SATA, Devilbiss and Iwata. All make some great guns but an expanded choice would have been nicer.
After more research I really liked the sound of Iwata guns and did eventually find a UK dealer selling the top of the range W400 for £345 which wasn't far off the price of the SATA. But by a stroke of luck I found an exdisplay but unused W400 on ebay for £100. At that price I hit the buy-it-now as quick as I could.
Iwata W400
This will be my first pro level gun and I'm hoping it will enable me to take my spraying skills and finishes to the next level. I'll also have a two gun setup now where I can setup my existing Kestrel AeroFura gun with a 1.8mm tip for priming and use the Iwata 1.3mm as my base and clear gun.
MJL21193 said:
That's a really good point, that I hadn't considered. I think the issues would be that you'd want the mask to be reliable (for eye protection too, as pointed out by posters here) so I'd probably buy a proper mask.
You'd then need to supply a small diameter hose connection, which means you need substantial pressure, to overcome the static losses in the hose. I think this is what would make the job more difficult to do with a DIY setup.
A larger diameter hose could be used, but I guess it would probably get a bit cumbersome. Plus, you really wouldn't want to get it wrong, considering it's providing you with clean air.
I have now confirmed from both the mask and compressor manufacturers that a 3HP Sealey SA22503 compressor and a Devilbiss MPV-623 full face mask will be compatible. With a filter and hose I expect the two to be over 400GBP. Just got to pluck up the courage to dent my bank balance again...
ShinOBIWAN said:
Wow. Serious bit of kit. Why are those guns so expensive - i.e. what do they do over the cheaper ones?
sploo said:
I'm really not sure Gordon. I've only been spraying using a compressor and gun setup for about 2 years now and during that time I have owned one and only one gun - the Kestrel AeroFura. So my practical knowledge of the differences between guns is very, very limited at best.
First off, I think with anything that's 'top-of-the-range' you pay a disproportionate amount more. Its the same with any consumer product and maybe non more so than audio. So I'm guessing the diminishing returns rule applies to spray guns too. I certainly don't believe you need to spend a great deal of money to get a great finish. My £45 Kestrel gun is brilliant I think, or maybe because I haven't had a pro gun I don't have a great perspective on what brilliant is. Maybe I should say the Kestrel offer great results for the money instead.
From what I've read on a couple of US spray forums, the better guns lay paint down with less orange peel, with better material transfer efficiency and metallics go on more evenly and uniform. I think its mainly down to how well guns atomise the paint, this requires precision engineered aircaps and needles which in turn requires precise machining not to mention extensive research and fluiddynamics modelling. I should imagine cheaper guns, whilst good, haven't had the same R&D and machining.
I really don't think you can say the more expensive guns are better built as in materials used for construction. But I'd assume expensive guns do have more parts availability and shelf life. So they're likely to supported and catered for long after they're no longer produced making the expensive gun a long term investment.
Most of this is pure speculation on my part though. I'll certainly let you know how I get along with Iwata once it arrives and what, if any, areas it improves upon over my existing budget gun.
ShinOBIWAN said:
Yea, I'd be very interested to find out how you get on with it.
I spoke to a mate who's a professional auto sprayer today (don't get to chat to him very often). He tells me he's using waterbased paints now.
He also made the point that 2K solid colour coats are usually used when you're not going to use a clear coat on top. However, as my urethane painted blocks are (nearly two weeks after painting) still pretty soft, I'm moving towards the 2K version, regardless of if I use a clear coat or not.
On the subject of the test blocks, the joins on the raw MDF block are easy to see, with graining across the edges. This is understandable, as it's effectively the primer coat. However, it's still too soft to consider sanding it and spraying a top coat.
Of greater interest are the other two blocks - one sealed with poly varnish, the other with Bonda G4. The varnished block is showing clear signs of the joins all round - it's very subtle, but definitely visible.
As far as I can see, the G4 coated block is pretty much OK. I'm not going to count any chickens yet, as I don't think the urethane in its current state is going to be a solution (too soft), but it is indicating that the G4 might be worth pursuing.
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I got the 7hp single to three phase converter this morning. Its a bit battered but my uncle says its been serviced regularly. I can't complain about the price as I got it for virtually nothing.
Not too happy about the performance though, it seems to be struggling with the 3kw load from the compressor and can't start the motor until you press a little button on the converter labelled 'boost'. My uncle was explaining it but most of it went over my head. Apparently the current requirements for startup of large electric motors is a magnitude larger than the constant draw once its actually running. The boost button gives a short but high current burst to get these large motors running.
This means that after the psi in the tank drops below a certain threshold, engages the pressure valve and turns the motor on I have to walk over to the converter and press the boost button otherwise the motor just buzz's and never starts.
I've been told I need one of the newer capacitor run converter's and about 10hp for over-sizing. I've looked at the prices of these and no way is all I'll say.
Not sure whether to stick with this and let it drive me nuts or just get rid and go for one of the dual 3hp compressors with will run on single phase.
sploo said:
Bummer I was sorta hoping the urethane would be winner. Jeez this is turning out to be a never ending quest for something so seemingly simple.
Keep up the excellent work Sploo, I don't have the time to investigate this to the extent you are. So I'm pinning my hopes on you providing a recipe to prevent it.
ShinOBIWAN said:
Yes, what you're experiencing is known as 'start up' or 'inrush' current. I had the same problem with the dust extractor - it could be run from a 9amp supply, but because it doesn't have any sort of soft start, it tries to pull about 16amps on startup, so needed a separate line installed in the garage (it would pop a 13amp fuse if used with a standard mains plug).
You could get a suitable petrol generator, that produces sufficient HP at 3 phase, but I don't know what that would cost. If you wanted to be a bit mad, it might be possible to connect a rectifier from the mains to a car battery (single phase AC -> DC) then connect the battery to a 3 phase inverter (DC -> 3 phase AC). A car battery will allow very high current draws, but the 3 phase inverter would also need to be capable of high current.
If the boost switch on the converter you have just overrides some overload cutout circuitry, then you could modify it to be permanently on - somewhat dangerous though. If the button provides a capacitor like boost, then it won't help.
ShinOBIWAN said:
I don't have the time either, but I want to find a solution!
It may well be that a second coat of the urethane will work, but it's just too soft at the moment. Even where I sprayed a thin coat on a test piece you can still scratch it with a fingernail, so I don't think it's ever going to dry tough enough for my liking.
To be honest, using the G4 is actually pretty easy - it paints on with a brush, clean up is OK. Given the number of coats required, it's actually easier than spraying (due to the prep and clean up required when using the gun).
The Bonda G4 is does look very promising, and I might have a backup plan with the MDF sealer that I've ordered from the local hardware shop. If the courier with my Jordan's arrives soon I can go and pick it up and get some wood cut to make some test blocks 😀
What finish colour should I get to the highlight the lines as much as possible? I was going to use gloss black, but I'm wondering if a really bright metallic silver (plus lacquer) would be better? I'm going to use rattle cans.
What finish colour should I get to the highlight the lines as much as possible? I was going to use gloss black, but I'm wondering if a really bright metallic silver (plus lacquer) would be better? I'm going to use rattle cans.
richie00boy said:
It's certainly worth a look. There's got to be something that does the business.
richie00boy said:
I think just about anything will show the lines if they're going to happen. On the gloss black blocks (cellulose) the paint isn't that thick, so the lines are quite sharp.
The white urethane has been painted on very thick, and the lines are much more subtle, but if it's there I reckon just about any smooth shiny finish will show it. No point in spending loads of cash on a fancy paint if you're just testing.
richie00boy said:
You'll definitely find the bright metallics are the toughest colours to both spray and the most prone to highlighting any surface imperfections that are either present in the primed surface the metallic goes on to or any imperfections that develop later on such as joint creep back. In fact these are so sensitive that I can clearly see the 400grit sanding marks in the primer that the metallic is sprayed over!
Solid colours hide the imperfections of the base only you've only got to really worry about your clear.
The best colour to use if your having problems with joints showing through the paint would be white with clear coat. Its a solid colour and because its bright, the contrast of the gloss in the clear is much reduced compared to say black.
Over £1k's worth of guns:
I had a visit from the Iwata rep today and he's lent me two waterbased configured W400 guns to trail in my search for a decent waterbased aircap and nozzle/needle setup for my W400.
At the moment my W400 is setup for solvent based but I'm wanting a set of water based parts that I can swap around as and when. The idea being that I can spray a water based base and then can switch to the solvent setup when spraying clears.
He's lent me two different setup, one is a split nozzle type that atomises the paint both before and after nozzle and the other is a regular after nozzle atomisation only. Both are good apparently but suit different people depending on their technique and products.
I'll be having a play with all three guns this weekend.
BTW If you need a gun, definitely checkout the Iwata's. The service I've received has been out of this world.
An externally hosted image should be here but it was not working when we last tested it.
I had a visit from the Iwata rep today and he's lent me two waterbased configured W400 guns to trail in my search for a decent waterbased aircap and nozzle/needle setup for my W400.
At the moment my W400 is setup for solvent based but I'm wanting a set of water based parts that I can swap around as and when. The idea being that I can spray a water based base and then can switch to the solvent setup when spraying clears.
He's lent me two different setup, one is a split nozzle type that atomises the paint both before and after nozzle and the other is a regular after nozzle atomisation only. Both are good apparently but suit different people depending on their technique and products.
I'll be having a play with all three guns this weekend.
BTW If you need a gun, definitely checkout the Iwata's. The service I've received has been out of this world.
Hey guys.
I have not been following this thread, but just popped in to see what's going on. Spray guns, eh?
Verrrry interesting. At work we spray our fine art prints on canvas. http://mauigiclee.com We use both solvent and water based coatings in conventional guns. (I'm not the coating guy)
But this past Tuesday I say a demo of the low pressure, high volume spray gun. Big fat hose and a turbo compressor the size of a small floor standing speaker.
I gotta say, it worked great! I've never used a spray gun before and I got great results. Very little over-spray and paint loss is what they tell me the advantage is. Far less of what is sprayed goes in the air. Seems super easy to use. Water based coating is what we sprayed.
Here's the kicker. The rig I used which is the big air supply costs about $1500 US with gun and everything! And they make a smaller (noisier) compressor that costs about $250 gun included. Amazing.
A lot of the auto retouch guys here are using these now.
Sorry if these have been discussed, but I thought I would share my experience with he new system. The brand name is in my notes at work, I'll post it tonight.
I have not been following this thread, but just popped in to see what's going on. Spray guns, eh?
Verrrry interesting. At work we spray our fine art prints on canvas. http://mauigiclee.com We use both solvent and water based coatings in conventional guns. (I'm not the coating guy)
But this past Tuesday I say a demo of the low pressure, high volume spray gun. Big fat hose and a turbo compressor the size of a small floor standing speaker.
I gotta say, it worked great! I've never used a spray gun before and I got great results. Very little over-spray and paint loss is what they tell me the advantage is. Far less of what is sprayed goes in the air. Seems super easy to use. Water based coating is what we sprayed.
Here's the kicker. The rig I used which is the big air supply costs about $1500 US with gun and everything! And they make a smaller (noisier) compressor that costs about $250 gun included. Amazing.
A lot of the auto retouch guys here are using these now.
Sorry if these have been discussed, but I thought I would share my experience with he new system. The brand name is in my notes at work, I'll post it tonight.
Ant, where is it you live again, I've got a white van and a crowbar and fancy coming round your place tonight. 😉
Michael, I've only sprayed using a turbine based HVLP system, so I'm quite used to the way it works. Doesn't get the greatest atomisation, but seems to do the job. Would love to have a play with a decent compressor and those Iwata guns though.
Michael, I've only sprayed using a turbine based HVLP system, so I'm quite used to the way it works. Doesn't get the greatest atomisation, but seems to do the job. Would love to have a play with a decent compressor and those Iwata guns though.
I have sprayed silver and clear before as I refurbished one of my alloy wheels.
So do you think I should try for silver then for my block test? I want it to show the faintest little line, so that if nothing shows then I know it will be even better with more forgiving finishes.
So do you think I should try for silver then for my block test? I want it to show the faintest little line, so that if nothing shows then I know it will be even better with more forgiving finishes.
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