HVLP investigation

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MikeJhn

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This is a copy of some of my posts on a Forum discussion on HVLP units, some of the reading flow may be off as others posts are not included, my first investigations concerned trying different units available on the market.

1. Earlex 5500, two stage turbine, impressed in the first instance, especially on the lack of overspray and the control over the paint content of the spray, the patten control was also impressive, not impressed with the constant bleed gun as it kicked up a lot of dust when not being used.

2. Apollo 1200 again a two stage turbine, gun was not very good, considering the increase in cost against the Earlex, again a constant bleed gun, see later comments.

3. Apollo 1300, big step in price, but also spec, this is a three stage turbine with a professional no bleed gun, the standard of finish compared to the above two is a quantum leap over them, its a moot point if the €100.00 increase is worth the extra.

4. Fuji Mini-Mate, another €100.00 up in price, but what a difference, the one I used had a gravity feed gun of 600ml this was so much easier to use, (lighter) it also had a flexible tube feed which I found made the gun go where I wanted, I had not realised how awkward the others where until I tried this on the Fuji.

It seems as with all things, you get what you pay for, the lighter gun on the Fuji made use that much easier, the others had a 900ml bottom feed gun and where awkward to use in confined space’s (inside cupboards and draws) the main difference was the standard of atomisation from the given guns and turbines and the tightness of the spray pattern, without doubt the Fuji was the best turbine and gun, much more controllable and consistent with its delivery of air and paint to the gun and less overspray, the gun controls where easier to use and the standard of paint finish is up there with the best, I ended up with some glass smooth finished machined MDF, admittedly this took some work and a lot of de-nibbing on the first coats.

I did not get a chance to try different needles and spray nozzles in all of the guns and am sure this would make a difference to the finish achieved.

conclusion:

Earlex: perfectly capable of spraying outside furniture, fencing, handrails, decking and walls, but not a fine finish machine, let down by the constant bleed gun.

Apollo 1200: As above with the reservation that the gun is not as good as the Earlex.

Apollo 1300: Quantum leap above the other two, the three stage turbine and a decent no bleed gun does make a difference, handle on the gun got a bit warm, I think due to the short feed tube, could achieve a better finish with a smaller needle than the 1.8 supplied with it.

Fuji Mini-Mate: I am no guru where spraying is concerned, but this gear made me look like an expert, the finish was outstanding for not a lot of extra effort, whether it is worth the extra cost is up to you, if you want to finish furniture to a professional high standard, then this is it, this unit came with a 1.3 needle, I can only imagine what the Fuji four stage turbine spray units offer.

Had a chance to use a Fuji four stage turbine unit over the week-end: Drool Drool, not only even better, but so much quieter as well, more like a small domestic vacuum cleaner, did not realise how noisy the others where until I heard (or did not hear) this one, now it all comes down to what this poor old pensioner can afford. All say Ahhh.

Had a chance to use a few different spray guns over the last few weeks and these are my observations:

Some of the cheap guns on e-bay are very good, but must be considered a throw away item, nearly all of them have metal handles that tend to get uncomfortably hot after a surprisingly short period of use, if looking for a gun, get one with a rubber covered handle if you are going to spray anything of any size, but you do get what you pay for.

Needle size does make a difference to the atomisation of the material being sprayed, the finer the needle/nozzle set the finer the atomisation, not really a surprise, but the amount of work needed to get the correct viscosity of the material is a balance between the needle size and the power of the turbine, a four stage turbine can spry Emulsion paint without thinning with a fine pointed needle, therefore a better finish is achieved without too much de-nibbing in between coats.

The lower power turbines must use a courser needle to spray the same material, but will not have as fine a finish on the work, therefore more rubbing down between coats.

Of course all of this can be side stepped by thinning the material being sprayed, you will then get into the realms of trying to match the material viscosity between each mix, when spraying larger items this can be a pain, even with a viscosity cup especially the mess you tend to make of the bench and surrounding area.

I did not find a lot of difference between the Fuji T70 gun and the SES Silver-Pro, this gun is supplied with a lot of turbine units, but costs about €100.00 compared to €250.00 for the Fuji, the Fuji gun is a work of art and just gives that “I’m doing a good job” feel to the work. :wink:

Also been looking at building my own turbine unit, will post when I have the cost together.

Still looking, but so far have sourced a three stage bypass vacuum motor at about £120.00, : http://www.ebay.co.uk/itm/LAMB-AMETEK-1 ... 0560838921 I would have to build my own housing at lets say £20.00, gasket material £5.00, filters £10.00 x 2, hose with fittings £35.00, gun £100.00, feet and handle for case £10.00, sound deadening material £10.00 come to £320.00, the Apollo 1500-3S is available at £324.00 here: http://www.airsupplies.co.uk/apollo-pro ... o_s=gplauk so it sounds like a waste of time and effort to make one, unless I can source a four stage vacuum motor for the same cost, have only found four stage units in the US so far.

Thought this may be useful information:

Bypass motors work independently from the vacuum/blower air. A separate fan is used to direct cooling air over the armature and field. It is important to ensure that the cooling air does not mix with the vacuum or blower air. Cooling air is typically made available through an filtered egress in the equipment housing. Bypass motors come in two configurations: Peripheral Bypass and Tangential Bypass.

Bypass motors are available in single and multiple stages. The stages are used to create more pressure if used as a blower or more lift if used as a vacuum.

Found this on e-bay: http://www.ebay.co.uk/itm/Lamb-Ametek-1 ... 1207650000 with two of these I would end up with a six stage unit, so using some additional costs for a bigger case to hold two motors, housing at lets say £30.00, gasket material £20.00, filters £10.00 x 4, hose with fittings £35.00, gun £100.00, feet and handle for case £10.00, sound deadening material £15.00 come to £383.00, the Apollo 1500-3S is available at £324.00, but that is a three stage unit so for £60.00 more I can build a unit twice as powerful to allow thicker paints to be sprayed, shame I have already bought the Fuji four stage unit :lol: But I may build one just for the fun of it and see how it turns out.

Unfortunately flow is not the only critical element of the HVLP system, consistent pressure is also required at the nozzle end of the gun, as the delivery tube is decreased in diameter the pressure drop caused by the restriction becomes more important, that is why a multi stage unit even though it may produce a lower CFM holds its pressure better any two stage unit as generally found in most vacuum cleaners, two stage HVLP systems typically deliver a pressure of 4:5 psi, as the stages are increased the pressure increases until the maximum required at the four stage units at 10psi, beyond this bounce back and overspray start to become a problem again, even at the lower pressure restriction valves are often required when working inside a closed sided work piece, e.g. a bookcase or draw.

Most manufactures of vacuum motors quote CFM unrestricted, this unfortunately bears no relation to the performance of the cleaner itself as at the end of the hose the CFM has reduced considerably.

But buy your vacuum cleaners now, since September 2014 the EU issued an edict that banned motors above 1600watts from being manufactured or imported to the EU for vacuum cleaners, soon this wattage is to be lowered to 900watts, so CFM/efficiency will become more important to vacuum cleaners than ever before.

Quick update, anyone who has painted raw MDF especial cut surface’s will know the difficulty of the raised surface and the need to de-nib, spaying with the HVLP heats the paint as it mix’s with the air in the gun, this dries almost instantly it hits the surface and does not raise the surface as much as any other treatment, the need for de-nibbing is greatly reduced and makes life much easier, still playing with this as I am sure with a bit of experimentation I could reduce this further.

Hope someone finds this useful.

Mike
 
Glad you like it Matt, it took a lot of time and effort to get to the conclusion that I needed a Fuji Four stage, lucky for me one came up on e-bay in the wrong section and I got if for not a lot, not as much of a bargain as my £10.0 Kity 439 PT though.

Mike
 
One of the annoying things about spraying is the capacity of the gun against its weight, more paint the heavier it gets, Fuji have brought out a 2Quart remote pot that does not need a compressor to run it, if you have a four stage turbine or over it has the capacity to pressurise the pot and supply paint to the gun: http://www.axminster.co.uk/fuji-2qt-pre ... kit-101564 I have not taken delivery of mine yet, but will report back on its usefulness.

Mike
 
Hi Mike

I know it's been a while since you started this thread but if you're still about and checking it I'd be really grateful for your advice.

I've been looking at the Fuji HVLP units for many years but other than cost I've always been nervous that they won't deliver what I hope....namely a top pro finish on furniture (mainly mdf) and spray walls and ceilings around the house (possibly with the addition of the pressure pot).

It seems like you've had good experience with Fuji and other units so I'd be grateful for your advice:

1. Is the Fuji Q4 capable of delivering the above?
2. Do water based paints (Dukux Diamond for walls etc and Rubbol Satura for satin finish mdf) need to be heavily diluted or spray well out of the can?
3. Can it spray zinsser BIN primer (my other concern with this is cleanup but maybe a cheap gun could be dedicated to it?). I do like BIN on mdf so a quick way to lay it on as a single or two coat primer would be great!
4. Although likely out of my price range Axminster sell a Q5 now. However I've not been able to find any reviews on it. Would this be worth the extra over the Q4? PSI is only a little higher and also could the added psi not result in more overspray especially for a total novice (ie me! :) )
5. Btw how did you get on with the pressure pot you got for your MM4?

I know I've directed this post towards Mike because of the nature of the thread he started but it goes without saying that I and I'm certain many others on the forum would greatly benefit from the advice and experience of others with Fuji and other HVLP setups.

Many thanks for any help and advice you can give!!!

Thanks a lot!

Aidan

PS - are the Morells coloured lacquers and other finishes better to spray especially for mdf than BIN + Rubbol etc? Ie cheaper, less toxic, dry faster, more durable finish, clean easier, etc?
 
1. Is the Fuji Q4 capable of delivering the above?
The Fuji Q4 is a very capable machine and will do all I require of it, as I said in the above review it heats the paint as it passes through the turbine and lays onto the workpiece very evenly and dries almost immediately, this prevents excessive de-nibbing of MDF and I find it a great boon

2. Do water based paints (Dukux Diamond for walls etc and Rubbol Satura for satin finish mdf) need to be heavily diluted or spray well out of the can?
With the different needle and nozzle combinations available I have not found a paint I can't spray without dilution, takes a bit of experimentation, but is possible.

3. Can it spray zinsser BIN primer (my other concern with this is cleanup but maybe a cheap gun could be dedicated to it?). I do like BIN on mdf so a quick way to lay it on as a single or two coat primer would be great!
I have never used that medium, so am unable to advise its use.

4. Although likely out of my price range Axminster sell a Q5 now. However I've not been able to find any reviews on it. Would this be worth the extra over the Q4? PSI is only a little higher and also could the added psi not result in more overspray especially for a total novice (ie me! :) )
The main difference between the Q5 and the Q4 is the speed control on the Q5 this allows a reduction in pressure to the gun with the associated reduction in bounce back, but a better control of the paint volume, the only problem I see with the Q5 is that to turn this control up or down needs a trip to the turbine unit to turn the knob, whilst this may not be a problem once you have it set up, I see it as very waring when trying out a new medium.
The Q4 on the other hand has a volume reducing valve at the end of the delivery tube under the gun, so immediately available to experiment with a new volume setting, now whether this is better than a speed control, I don't know, one adjusts speed, hence volume and pressure and one adjusts volume only, would be interested to find out if anyone has the Q5 and previously had a Q4.

5. Btw how did you get on with the pressure pot you got for your MM4?
I actually have a Q4 not a MM4, the only difference being the sound proofing of the Q series, the pressure pot works very well, but I would not like to try it on anything lower than a four stage turbine.

Morells sprays straight from the can, dry almost on contact, can't comment on durability as its only been three years since I sprayed my wardrobe doors, but they still look good, with the correct spraygun cleaner, from Morells the gun and pot cleans up just fine, I use their second grade gun cleaning fluid and it does what its supposed too.

Mike
 
Hi Mike

I'm still researching a spray system and came across Wagners XVLP. Do you have any experience with this and how these units compare to the Fuji?

Also, do you have any extraction or booth (or do you spray outdoors)? What s the overspray like on the Fuji?

Many thanks again for all your help and all the information in this thread!
 
Very dubious about the Wagners XVLP as it is only a two stage unit, and that is only mentioned once in all the hyperbole they put on their site, I have no experience of their products, so am only speaking from what I have seen on the site.

I generally do not use extraction, but if I am spraying anything toxic I use my Trend full face helmet, most of my spraying is done in a piggery outside my workshop, open fronted and open roofed, overspray on any HVLP system is far less than any compressor system, even those that purport to be HVLP, the point of HVLP is Low pressure with lots of air to atomise the paint, overspray on the Fuji is minimal, I don't seem to find paint anywhere other than where its supposed to be.

As I have said before the more stages the turbine has the better it can cope with a thicker medium, stage increase only results in a very small pressure increase which can be conpensated for at the gun, with the paint volume control, the only way to find this out is to try some of the equipment available at hire shops, or just jump straight into a three stage system which I recommend as a minimum.

You may also find this thread interesting: another-what-hvlp-question-t101904.html

Mike
 
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