On Mar 22, 8:46=A0am, gary <[email protected]> wrote:
> I need suggestions on pain spray gun to use on oil and water based
> paint. I don't know anything about spray guns and would appreciate any
> hep you can give me. I have been looking on Amazon and the prices seem
> to be inline but I don't which gun to order.
Hi, Gary. When considering a high pressure gun or a CAS HVLP gun, a
gun that shoots both must come with different tips. When you shoot an
oil based (or solvent based) material such as paint, lacquer, poly,
etc., you will need a gun that has the equivalent of a 1.1mm to 1.5mm
tip. Most spray guns that are targeted for oil used come with a
1.4mm. **Depending on the material** you are trying to spray, that is
usually the best all around size.
When you shoot water based lacquers and paints, you need to go to the
manufacturer's MSDS sheets and review their recommendations. Many
water based lacquers behave will with a 1.4mm tip, but some require
larger. For latex enamels, the best size for the thicker paints is
somewhere +/- the 2mm range.
This of course is considering that you have plenty of compressor to
back up one of these guns. It doesn't take much if you are careful; I
spray with a 2hp compressor on my HVLP CAS gun frequently. You will
find that a reliable, powerful compressor is just as important as a
good gun.
If you buy a true HVLP system, it will come with different tips, or
others will be available. The manufacturer of the individual guns
will have tips (or "aircaps" in HVLP terms) they make to shoot
different materials. These will vary by manufacturer.
If you are new to spraying, google around this newsgroup as there is a
lot of good information on technique and gun set up.
Robert
"Digger" wrote:
> 1. Never less than 3/8 diameter air hose for run to compressor
> ...took
> me a great deal of trail & error to learn that little lesson.
---------------------------------
Best investment you will ever make as follows:
Wait till H/F runs a sale on Goodyear hose, then buy two (2), 1/2" ID
x 50 ft, rubber hoses, then equip them with quick connect couplings.
Buy a quality 25 ft, 3/8" hose, equip with quick connect couplings for
the final hook up to gun.
I find using a pressure pot worth the expense.
YMMV.
The above eliminates hose pressure drop problems when spraying.
Lew
"Bill" wrote:
> Are you saying you run 125' of hose between the compressor and the
> spray gun? Like a big "shock absorber", huh?
------------------------------------
Working in a boat yard is a little different than in your garage.
Many times 125 ft of hose makes life simpler or even possible.
Since regulator is in the pressure pot, you're dealing with line
pressure for all 125 ft which helps hose to function like an
accumulator or to use your words, "shock absorber".
"Digger" wrote:
> Good solid advice Lew.
>
> My own little shop is fully staged throughout with 3/4" schedule-80
> and
> an inground run extending to the front of the house for routine tire
> and
> other pressure needs (my own version of a pressure pot <g>). Within
> the
> shop are quick disconnects located about every 8' around the
> perimeter
> and 1/4" coiled drops over benches.
>
> The reason I mentioned the minimum 3/8" is because no one ever told
> me I
> shouldn't use 1/4" when I asked about buying and using my first gun.
> Even the manuals did not address hose size. Everywhere I looked were
> specs for CFM, SCFM and min/max Pressures, but virtually nothing
> about
> hose size. Never took auto shop in high school and had not a clue.
> I needed a picture and no one drew it for me.
>
> Threw away a perfectly good gun because I had absolutely no idea
> what I
> was doing or how to get it to work right. So, thought I might
> mention
> this for the benefit of the original poster ...perhaps it will help
> him,
> or save someone else from an unpleasant experience similar to mine.
---------------------------------
Whether you are dealing with a fluid, compressible or non
compressible, or you are talking about the electrical world, you must
deal with resistance when you are trying to move energy from one point
to another.
Resistance to flow is proportional to the cross sectional area of the
pipe/hose or wire involved.
The cross sectional area is proportional to the square of the diameter
of the pipe/hose or wire.
Bottom line.................................
A larger size pipe/hose or wire reduces resistance losses (heat),
which saves money over the life of the device.
Bigger is better applies to a lot of things.<G>
Lew
I wrote:
>>Resistance to flow is proportional to the cross sectional area of
>>the
>>pipe/hose or wire involved.
--------------------------------
"alexy" wrote:
> Good summary. But just to clarify the obvious, resistance to flow is
> INVERSELY proportional to the cross section...
-----------------------------
DUH!
See what happens when early in the morning you don't proof read your
stuff before you post it?
Thank you for cleaning up my mess.
Lew
On Mar 23, 6:19=A0pm, "Lew Hodgett" <[email protected]> wrote:
> "Bill" wrote:
> > Are you saying you run 125' of hose between the compressor and the
> > spray gun? =A0Like a big "shock absorber", huh?
>
> ------------------------------------
> Working in a boat yard is a little different than in your garage.
>
> Many times 125 ft of hose makes life simpler or even possible.
>
> Since regulator is in the pressure pot, you're dealing with line
> pressure for all 125 ft which helps hose to function like an
> accumulator or to use your words, "shock absorber".
I bought my first pressure pot (DeVilbiss) with an HVLP gun in 1989. I
don't want to say what I paid for that set-up.
It was such a quantum leap up from a basic cup-style gun that I never
regretted it.
Turn off the air to the gun.
Open the trigger,
Watch the fluid squirt out adjusted to a nice arc.
Turn on the air, adjust fan to blow apart previously determined fluid
flow.
Done.
Bullet proof, never stutters, sprays upside down, much lighter to hold
over extended periods...just all-in-all nothing to talk about.
I later added an Iwata gun which made spraying even more fun.
And today, one can buy a pot fed ( 2 litre ) with a decent HVLP head
for under $100.00...again, nothing to talk about. I just bought an
additional 20 litre pot for $69.00, just for cleaning/back-draining
the hose (into a poly sleeve/liner)
On 3/22/2011 10:46 AM, gary wrote:
> I need suggestions on pain spray gun to use on oil and water based
> paint. I don't know anything about spray guns and would appreciate any
> hep you can give me. I have been looking on Amazon and the prices seem
> to be inline but I don't which gun to order.
nailshooter41 is right on point, but unless you are really experienced
with shooting (spraying) I would also add the following...
1. Never less than 3/8 diameter air hose for run to compressor ...took
me a great deal of trail & error to learn that little lesson. A large
dia hose acts as an air reservoir, a header, providing more constant and
even airflow. Pull the trigger on 1/4 in. feed and air is immediately
dumped. The gun must then wait for the volume to catch up, over and over
again. Not sure if my explanation is clear, but hope it makes sense.
2. Use an air filter!!!!
3. Pay attention to manufacturer recommendations for thinning and
spraying, or in other words "RTFM". Thinning agents and solvents are not
necessarily always the same thing.
errata...
Spent about $275 on my first gun and never could get latex to spray well
...got frustrated, went to Harbor Freight and spent $15 on a throwaway
industrial sprayer (91011). Too my surprise, everything worked perfectly
- after changing to a 3/8 in. airline. Go figger!!
While in learning mode, cheap throwaways are sometimes the best way to
start out. I still use that same $15 sprayer for all water based fluids
and have subsequently bought another cheap model gun with a 1.4mm tip.
Some folks just order an extra 1.4mm and drill it to 2mm for less than
the cost of two guns. For myself, I threw away the second gun and kept
the tip. I now have what I need for both, oil & water.<g>
Regardless, always purchase additional paint cups w/plastic lids so that
you can swap out cups with a cleaning agent immediately, and 30 min
later go back to the primary cup, remove the lid, and spray another
coat when ready.
There are pros & cons to all the recommendations you will read, but my
advice is to learn cheap while gaining experience and a better
understanding of what ultimately suits your needs best. Some may
disagree, but I hate throwing huge sums of money at a problem while I'm
only in the learning stage. Sorta like purchasing a unisaw for $3,500
before you ever rip your first board ft.
on HVLP...
I'd bet I have sprayed more lacquer and clear acrylic into my neighbors
yards than I have ever actually applied to a given project. At $30.00+ a
qt., a conventional pressure rig can easily consume 1.5 qts on a project
as small as a computer desk or shelving unit. Most lost in over spray.
Most pros today have already moved to HVLP systems of one type or
another, specifically for the reasons stated above ...reduced over spray
and better control, which eventually translates to money saved.
Startup cost for a good HVLP 3 stage air turbine and spray gun with
assorted tips, is really high and perhaps not the most inexpensive way
to learn. If you have that kind of money to throw away, please call me.
My suggestion would be to rent one and try it for a day, before
investing huge bucks.
--
Digger
Bob O'Dell
On 3/23/2011 4:49 PM, Lew Hodgett wrote:
> "Digger" wrote:
>
>> 1. Never less than 3/8 diameter air hose for run to compressor
>> ...took
>> me a great deal of trail & error to learn that little lesson.
> ---------------------------------
> Best investment you will ever make as follows:
>
> Wait till H/F runs a sale on Goodyear hose, then buy two (2), 1/2" ID
> x 50 ft, rubber hoses, then equip them with quick connect couplings.
>
> Buy a quality 25 ft, 3/8" hose, equip with quick connect couplings for
> the final hook up to gun.
>
> I find using a pressure pot worth the expense.
>
> YMMV.
>
> The above eliminates hose pressure drop problems when spraying.
>
>
> Lew
>
>
>
Good solid advice Lew.
My own little shop is fully staged throughout with 3/4" schedule-80 and
an inground run extending to the front of the house for routine tire and
other pressure needs (my own version of a pressure pot <g>). Within the
shop are quick disconnects located about every 8' around the perimeter
and 1/4" coiled drops over benches.
The reason I mentioned the minimum 3/8" is because no one ever told me I
shouldn't use 1/4" when I asked about buying and using my first gun.
Even the manuals did not address hose size. Everywhere I looked were
specs for CFM, SCFM and min/max Pressures, but virtually nothing about
hose size. Never took auto shop in high school and had not a clue.
I needed a picture and no one drew it for me.
Threw away a perfectly good gun because I had absolutely no idea what I
was doing or how to get it to work right. So, thought I might mention
this for the benefit of the original poster ...perhaps it will help him,
or save someone else from an unpleasant experience similar to mine.
Thanks,
--
Digger
Bob O'Dell
The first question is how much is reasonable in $$$,
then you get suggestions.
Some folks think that you can do it with this:
http://www.leevalley.com/US/wood/page.aspx?p=64638&cat=1,190,43034&ap=1
or
http://www.leevalley.com/US/wood/page.aspx?p=20048&cat=1,190,43034&ap=1
and finally:
http://www.spraygunworld.com/Information2/Turbine/Fuji/Mity4%20compressor%20Outfit.html
Soooooo....how much ???
On 3/22/2011 10:46 AM, gary wrote:
> I need suggestions on pain spray gun to use on oil and water based
> paint. I don't know anything about spray guns and would appreciate any
> hep you can give me. I have been looking on Amazon and the prices seem
> to be inline but I don't which gun to order.
Sometimes, for beginners (as with myself, at one time), it's hard to
interpret what you may read on the different sites, regarding spraying
techniques (not just spraying equipment). When you get your
equipment, it might be wise to go to an auto bodyman, a cabinet man,
etc., and pay them a reasonable fee, if they are agreeable to teaching
you (and more than you think are agreeable. Simply ask!), to teach you
a few nuances about spray painting or finishing techniques. Nor is it
so easy to learn by hit-or-miss techniques when reading the literature
that may come with the equipment. Hands on is a good teacher and it
helps to have someone on hand to guide you, when/if need be.
Sonny
On 3/22/2011 11:53 AM, Sonny wrote:
> Sometimes, for beginners (as with myself, at one time), it's hard to
> interpret what you may read on the different sites, regarding spraying
> techniques (not just spraying equipment). When you get your
> equipment, it might be wise to go to an auto bodyman, a cabinet man,
> etc., and pay them a reasonable fee, if they are agreeable to teaching
> you (and more than you think are agreeable. Simply ask!), to teach you
> a few nuances about spray painting or finishing techniques.
Evidently this may work if the person does not happen to also be a
welder. As has been written, "There's no free lunch in the welder's shop!".
Nor is it
> so easy to learn by hit-or-miss techniques when reading the literature
> that may come with the equipment. Hands on is a good teacher and it
> helps to have someone on hand to guide you, when/if need be.
>
> Sonny
On 3/22/11 10:53 AM, Sonny wrote:
> Sometimes, for beginners (as with myself, at one time), it's hard to
> interpret what you may read on the different sites, regarding spraying
> techniques (not just spraying equipment). When you get your
> equipment, it might be wise to go to an auto bodyman, a cabinet man,
> etc., and pay them a reasonable fee, if they are agreeable to teaching
> you (and more than you think are agreeable. Simply ask!), to teach you
> a few nuances about spray painting or finishing techniques. Nor is it
> so easy to learn by hit-or-miss techniques when reading the literature
> that may come with the equipment. Hands on is a good teacher and it
> helps to have someone on hand to guide you, when/if need be.
>
> Sonny
There are probably a lot of video lessons out there on the interweb.
When I have a repair to do on one of the cars, I've taken to checking
the internet for videos, first, before going to the repair manual.
Between youtube and all the other video sites, I usually find a decent
video done by mechanic or handyman showing the exact repair I need.
It's saved me a lot of time, frustration, & knuckle.
--
-MIKE-
"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply
Pat Barber <[email protected]> wrote:
>The first question is how much is reasonable in $$$,
>then you get suggestions.
>
>Some folks think that you can do it with this:
>
>http://www.leevalley.com/US/wood/page.aspx?p=64638&cat=1,190,43034&ap=1
>
>or
>
>http://www.leevalley.com/US/wood/page.aspx?p=20048&cat=1,190,43034&ap=1
>
>and finally:
>
>http://www.spraygunworld.com/Information2/Turbine/Fuji/Mity4%20compressor%20Outfit.html
>
>Soooooo....how much ???
>
>On 3/22/2011 10:46 AM, gary wrote:
>> I need suggestions on pain spray gun to use on oil and water based
>> paint. I don't know anything about spray guns and would appreciate any
>> hep you can give me. I have been looking on Amazon and the prices seem
>> to be inline but I don't which gun to order.
Pat raises excellent points above. I would include one other option
between the critter and the Fuji, and that is a low-end HVLP, such as
the HF/Rockler one or a low-end one from Earlex.
I have the HF/Rockler one and have been satisfied on a couple of
projects spraying oil-based enamel, although I definitely see me
"outgrowing" this unit if I do much spraying.
I also have a critter, which I love for small projects, and don't
anticipate outgrowing. I just used it to spray alkyd enamel on a 4'x
8' bookcase, which is clearly a stretch for the critter, but it is
great for smaller work.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
Lew Hodgett wrote:
> "Digger" wrote:
>
>> 1. Never less than 3/8 diameter air hose for run to compressor
>> ...took
>> me a great deal of trail& error to learn that little lesson.
> ---------------------------------
> Best investment you will ever make as follows:
>
> Wait till H/F runs a sale on Goodyear hose, then buy two (2), 1/2" ID
> x 50 ft, rubber hoses, then equip them with quick connect couplings.
>
> Buy a quality 25 ft, 3/8" hose, equip with quick connect couplings for
> the final hook up to gun.
>
> I find using a pressure pot worth the expense.
>
> YMMV.
>
> The above eliminates hose pressure drop problems when spraying.
>
>
> Lew
Are you saying you run 125' of hose between the compressor and the spray
gun? Like a big "shock absorber", huh?
"Lew Hodgett" <[email protected]> wrote:
>Whether you are dealing with a fluid, compressible or non
>compressible, or you are talking about the electrical world, you must
>deal with resistance when you are trying to move energy from one point
>to another.
>
>Resistance to flow is proportional to the cross sectional area of the
>pipe/hose or wire involved.
>
>The cross sectional area is proportional to the square of the diameter
>of the pipe/hose or wire.
>
>Bottom line.................................
>
>A larger size pipe/hose or wire reduces resistance losses (heat),
>which saves money over the life of the device.
>
>Bigger is better applies to a lot of things.<G>
>
>Lew
>
>
Good summary. But just to clarify the obvious, resistance to flow is
INVERSELY proportional to the cross section...
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
On Wed, 23 Mar 2011 15:19:06 -0700, "Lew Hodgett"
<[email protected]> wrote:
>
>"Bill" wrote:
>
>> Are you saying you run 125' of hose between the compressor and the
>> spray gun? Like a big "shock absorber", huh?
>------------------------------------
>Working in a boat yard is a little different than in your garage.
>
>Many times 125 ft of hose makes life simpler or even possible.
>
>Since regulator is in the pressure pot, you're dealing with line
>pressure for all 125 ft which helps hose to function like an
>accumulator or to use your words, "shock absorber".
Why not attach the gun to a 1/2" x 25' line connected to a 5gal air
pig which is connected to any old -long- air line?
--
You are today where your thoughts have brought you;
you will be tomorrow where your thoughts take you.
-- James Lane Allen