Spray equipment ?

[Dean]

The air adjustment knob is only ⅓ open, if that. I reckon I'm spraying at about 15-18 PSI or so.

WOW :eek:
Maybe that is the trick to "Major-quality" finishes.
I'll give it a try

[Soren]

..........Your compressor should handle both and of course the gravity feed HVLP will be easier on the unit but technique will play an important role as will the seals be ..............

A gravity gun seems like a waste of money for fence painting as is a good arnold suction gun! :eek:

I just checked the IWATA site, and that suggests that the HVLP is actually requiring minimum of 9 cfm, whereas the suction gun only requires 5-10 cfm ?

When I was at Supercheap at Ringwood the other day, they had an "HVLP" gun for $99 which supposedly only needed between 3 - 4 CFM to run !! is that worth it, to 'save' the compressor ?
:confused:

[turbo]

"MP so the S-770 2mm will spray lacquer OK, I need a cheapy to tie me over until I replace my samson(RIP!)dam cant seem too find the parts to repair it yet.

the star gun will suffice for spraying lacquer mate , could even get away with putting a larger nozzle , cap and needle in for spraying sealers etc , or go the reverse and have a smaller setup for colouring up or toning etc.

either way it will do the job for the home handyman.


ps - what do u need for ol' smason , i might have a few spare bits and peices from a couple of junk pile guns at work.

let me know and i will have a look.

[johnno402002]

ROFLMAO

How do you time your stick ?

I use a stick too, the flat one I use to stir the paint. Dip the stick into the paint, pull it out. Watch how far away from the end of the stick the paint breaks from a solid stream into droplets. The closer to the stick, the thinner the paint. Suprisingly sensitive.

regards,

John

[Shane Watson]

I use a stick as well....Never use a viscosity cup & the quality of finish was never compromised. But once you've mixed several thousand litres you get to know.....

[Harry72]

Yup stick yer paint!
Soren, dip the paint stick in and hold it out of the paint about 150mm, wait about 2 seconds then look how far the paint breaks into droplets(like Johnno said)
Depending how much paint your stick can hold on its surface is how much time you've got to judge it, ie use a stick with as much surface area as possible... a series of small holes drilled in you stick will increase the amount of time you can judge it for.

Denpending on what paint your using, with enamel and a 1.8mm nozzle 100mm is about right break distance, with poly and a 1.4mm nozzle go about 80mm or with 1.8-2.0mm nozzle you want about 100-120mm.
With the few goes I've had with pre-cat lac 1.4 nozzle 60-80mm, 1.8 nozzle 80-100mm
This is for a 10-20% thinning ratio.
See the pattern generating here... smaller the nozzle thinner you want the paint, if the paint needs to go on thick dont use a small nozzle(enamel/poly final coats).

Turbo, I need the outer sleave that the paint needle and spring assembley sits in, dunno what its called lost the parts# sheet years ago... and cant find one anywhere which is a bit funny, seeming you can still buy S90's new!

[Soren]

Thanks for that Harry72
I'll print it out and try my luck

[turbo]

harry

i know what your referring to , i will look in the spares tomorrow.

cheers

andrew

[violincrafter]

Hi Folks,

Anyway just wanted to drop a line on the subject of spray equipment. I have been using both the touch up gun and the HVLP Gravity gun and let me tell you the finish is SUPERB to say the least. Ive adjusted the HVLP for optimum performance and it really does reduce overspray and transfers more of the material to the work.

I have a 2.5hp 40ltr compressor that handles it quiet well without to many dramas. As a fact I tried a simple experiment to determine how if any strain is placed on the compressor. First I attached the touch up gun an let it "shoot" a test panel to see the amount of time when the compressor reaches the cut in point of 85 psi and working to 115 psi factory settings. The touch up sprayed for 28 seconds to reach 85 psi and the HVLP gun took 26 seconds of continual spraying. There was little difference between the two except the HVLP gravity had less overspray (in the air) than did the touch up gun.

I like both of them and thus far have given excellent results. The touch up has its advantages owing to work type and space as the gravity HVLP is slightly bigger and uses a pressure guage at its bottom making it longer with the hose attached.

Practice makes perfect and am very satisfied with the results.

[Asquared]

Evenin' All, I am also new to spraying and have been learning by trial and error. I too have a little GMC compressor (only cost $100) and I think it is good for about 5cfm. And I bought the el cheapo spray outfit from Bunnings that include a spray gun (1.8mm), blower, degreaser gun, tire inflator etc all for about $35! I then proceeded to spray a sunburst lacquer finish onto an electric guitar and the results were great (much to my surprise). Being small item and using only short bursts so the comp had no problems keeping up.

I have since bought a much better although still inexpensive spray kit that includes two guns both gravity feed: a 1.4mm regular gun and a 1.0mm touch-up gun. So far only used the little fella and it is working well. I use 35 - 40 psi and am wondering if that is too much. I tend to turn the feed control right down and use a very narrow fan, almost no fan at all. Still I seem to get a lot of overspray and the spray booth (garage) fills with a lacquer cloud.

I would love to have a general reference on the ins and outs of spraying but I haven't found anything on the web. Can anyione direct me to a basic spray painting reference?
Asquared

[violincrafter]

Hi Mr Asquared,

Theres not a great deal of info out there on this topic. However there are some "honky doree" forums that deal in spray painting in general.

The one I shall post the link herewith is in fact for automotive hot rods! Yes hot RODS! Well your probably thinkin what the hell has this got to do with woodworking? Well to some not much but to others -----" A whole lotta Rosie"! lol.

My jargon by no means is humour but rather a keen eye for detailing. If one can master the gleam and shine of a hotrod for show, then timber finishing would also result in this grand piano shine.

This site has lots of information on 2 pacs, enamel, acrylic lacquer, just to mention a few. If one can master a perfect finish in auto design then timber finishing would also be accomplished except for substrate coating and undercoat procedures.

Handling the spray gun incorrectly will give the same sort of results finishing auto or dining room furniture. Auto painting of which is "fun" will showw how good a spray painter you really are. I get a mirror finish without any buffing what so ever.

http://www.hotrodders.com/f19


Have fun reading this link. Its a good spray painters reference no matter what you intend on painting.

Have fun!!!

violincrafter

[Asquared]

Violincrafter, Thanks for the tip. Had a quick look and there is a lot there. As one of my loves is making guitars - electrics so far - , the "hotrod" paint jobs has some relevance!

Cheers
AA

[AshleyM]

Hi Violincrafter,
What make spray guns are you using?
Ash

[violincrafter]

Hi Folks!
I have used a couple of guns that work fine. The touch up gun is a trade air unit and this one (for me) performs very well and delivers a very fine atomization. The other gun is a high volume low pressure gravity feed gun from supercheap auto shop. It has various adjusters that need to be fine tuned but after a feww test patterns works very well also.

This one does have reduced overspray in the surrounding environment.

Heres a pic of both of them



As I mentioned earlier I did a test to see the difference between the 2. I may not have explained it fully but I tried the following

after the compressor reached its full tank capacity ( 40 ltrs at 115 psi) I used both guns to see how they differ in taxing the compressor.

There was very little difference between the gravity HVLP and suction touch up gun.

The touch up went for 28 seconds continuously before it taxed the comp down to the 85 psi cut in point.

The HVLP gun was allowed to work continuosly with a full tank and went for 26 second of continual spraying to tax the compressor to go down to 85 psi and then cuts in to refil the tank.

In my opinion both worked similar working times but HVLP had less overspray. This in turn makes it more environmentally friendly no matter what paint you use but especially 2 pacs. Thus gravity is essential owing to isocyanites in overspay regulations.

I am going to get a 770 gun but after being in a paint shop the other week it was pointed out that there are guns that are copies of the star 770 as in bunnings 770 gun.

The proprietor of a auto body shop sells the same thing but another generic and this also is a good gun and leaves a factory in asia from the back door export dispatch as the star 770 from the front in gloss advertising boxed package. As far as the carba tec HVLP unit its the same as the unit I have but mine comes with extra bottle, seals and grommets, extra nozzle and tip, and blow moulded storage box.

I know people will argue the point, but my friend at the auto paint shop is good enough advise for me. He orders them and I believe his advice.

Anyway each to their own but at the end of the day as another professional painter said to me long ago , " Its the spraypainter and his technique that makes or breaks the job". Runs will happen even with a $10000000.00 gun. As with "fish eyes, orange peel effect, and blushing in poor workshop conditions". Crazing and other problems are a result of poor workshop temperatures as is humidity blistering just to mention a few.

Anyway thats my opinion but am very happy with these guns.

Ps I have made a 1 litre pot from brass for the touch up gun to make it work even further. Two touch up guns for the price of one! Suits me fine ! I've achieved better results than any panel shop can do and I dont need to convince myself about it ! lol

PRACTICE MAKES PERFECT AS WITH TEST RESULTS NO TWO IF'S About IT!!!!!


Here it is :_

[Richardwoodhead]

Asquared, a couple of useful links..... On Major Panics rcommendation I contacted Mirotone re their Lacquer finishes (via the website). They rsponded with heaps of info on spraying technique etc... Worthwhile contacting...

http://www.ganet.org/dnr/p2ad/pblcations/paintbas.html
http://www.mirotone.com.au/locat.htm

Richard