HVLP question

On Wed, 16 Nov 2011 11:00:20 -0700, chaniarts wrote:

> I purchased a cheap HVLP gun at HF to do some spraying. The question I
> have is about pressure. the manual states to run it about 40psi, and
> never run it higher than that. i have a small regulator at the gun, and
> one at the compressor end. when i set the compressor regulator at 45, i
> get about 40 at the gun (i have to use about 75' of 3/8" hose to get
> where i need to spray as the compressor is a large tank in the
> garashop). however, when i start spraying, it drops down to the 20 psi
> range whilst i'm spraying, and going back up when i release the trigger.
>
> when i crank the pressure up at the compressor regulator, the pressure
> then, of course, goes up at the gun. when i start spraying, the pressure
> drops pretty quickly, then rises back up when stopping spraying.
>
> this is my first experience with an hvlp, so is this normal? is the
> 20psi during spraying good enough? it seems to be spraying a pretty fine
> mist at 20psi when i did my testing with plain water.
>
> what i'm spraying is mostly water anyway, so it shouldn't be too much
> different viscosity.
>
> thanks,
> charlie

Use a much larger hose for the first 60 feet.
basilisk

On Nov 17, 11:43=A0am, Larry Jaques <[email protected]>
wrote:
> On Thu, 17 Nov 2011 08:11:28 -0800 (PST), Robatoy
>
> <[email protected]> wrote:
> >> [email protected]
>
> >Even if the job isn't very big, I'm a pot-fed kinda fella. (PUT those
> >wisecracks away!!LOL)
>
> Too easy! =A0;)
>
> >So easy to adjust, sprays upside down. You can
>
> How often do you find yourself hanging by your ankles to shoot a bit
> of paint, sir? =A0Inquiring minds, y'know...
>
> >get the whole shebang for 60 bucks for a 2 litre.
> >The cleaning is only a bit more work, and just the reduced fatigue in
> >the spray arm alone is worth it. Currently, I own a couple of HVLP
> >guns, a 2 litre pot and a 5qt floor pot. Nice lightweight hoses and a
> >gravity fed HVLP with a 2 mil tip for thick stuff like Jay Cooke
> >primer.
>
> What do you use your guns for, Toy?
>
> >I can kick my ass for selling my Iwata gun, but it has since been
> >improved upon, but a bit spendy.http://www.danielsmith.com/Item--i-155-0=
30-005
>
> http://www.chicagoairbrushsupply.com/iwrg3mispgun.html=A0Save $75 if
> you haven't already bought one.
>
> --
> Most powerful is he who has himself in his own power.
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0-- Seneca

I was so thrilled with keeping 75 smackereoonies in my pockets that I
forgot to answer your question.

I do not like brushing paint. I do so much better spraying and signs
are perfect candidates for spraying primers, base coats, and other
trickery.

On Nov 17, 10:21=A0pm, Larry Jaques <[email protected]>
wrote:
> On Thu, 17 Nov 2011 16:33:13 -0800 (PST), Robatoy
>
>
>
>
>
>
>
>
>
> <[email protected]> wrote:
> >On Nov 17, 11:43=A0am, Larry Jaques <[email protected]>
> >wrote:
> >> On Thu, 17 Nov 2011 08:11:28 -0800 (PST), Robatoy
>
> >> <[email protected]> wrote:
> >> >> [email protected]
>
> >> >Even if the job isn't very big, I'm a pot-fed kinda fella. (PUT those
> >> >wisecracks away!!LOL)
>
> >> Too easy! =A0;)
>
> >> >So easy to adjust, sprays upside down. You can
>
> >> How often do you find yourself hanging by your ankles to shoot a bit
> >> of paint, sir? =A0Inquiring minds, y'know...
>
> >> >get the whole shebang for 60 bucks for a 2 litre.
> >> >The cleaning is only a bit more work, and just the reduced fatigue in
> >> >the spray arm alone is worth it. Currently, I own a couple of HVLP
> >> >guns, a 2 litre pot and a 5qt floor pot. Nice lightweight hoses and a
> >> >gravity fed HVLP with a 2 mil tip for thick stuff like Jay Cooke
> >> >primer.
>
> >> What do you use your guns for, Toy?
>
> Hiding your use, eh?
>
> >> >I can kick my ass for selling my Iwata gun, but it has since been
> >> >improved upon, but a bit spendy.http://www.danielsmith.com/Item--i-15=
5-030-005
>
> >>http://www.chicagoairbrushsupply.com/iwrg3mispgun.html=A0Save $75 if
> >> you haven't already bought one.
>
> >nice CATCH!!! Thankee kindly, Sir! I will order.
>
> Jewelcome.
>
> --
> Most powerful is he who has himself in his own power.
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0-- Seneca

What kind of stuff do I spray? A lot of Jay Cooke primer in my signs,
a lot of One-shot enamel in fades and back-grounds on those signs, the
odd piece of furniture, a quick refinish for an old couple's
kitchen... The rims on my kids car.... etc...

Robatoy wrote:
> On Nov 19, 4:58 pm, "Mike Marlow" <[email protected]>

>>
>> Do you have any problems with shrinkage?
>>
>
>
> Only when I swim in cold water.
> .
> .
> Come ON! Somebody had to say that.. Now. re paint...
> No problem with shrinkage.


Hell I have that shrinkage problem without the damned cold water...

--

-Mike-
[email protected]

On Fri, 18 Nov 2011 16:40:05 -0800 (PST), Robatoy
<[email protected]> wrote:

>On Nov 17, 10:21 pm, Larry Jaques <[email protected]>
>wrote:

>> >> What do you use your guns for, Toy?
>
>What kind of stuff do I spray? A lot of Jay Cooke primer in my signs,
>a lot of One-shot enamel in fades and back-grounds on those signs, the
>odd piece of furniture, a quick refinish for an old couple's
>kitchen... The rims on my kids car.... etc...

"Stuff", got it. Thanks.

http://www.haradhesive.com/jay_cooke.html Looks like good stuff.
Expensive?

--
Most powerful is he who has himself in his own power.
-- Seneca

>> Do you have any problems with shrinkage?

Robatoy wrote:

> Only when I swim in cold water.
-----------------------------
Nuther reason I came to SoCal.

"Throw another log on the fire,
Hustle up another cup of tea."

Lew

>
> what i'm spraying is mostly water anyway, so it shouldn't be too much
> different viscosity.
>
> thanks,
> charlie

My HVLP system has a turbo fan but I assume you are using straight
pressure HLVP conversion type gun. When I use a regular spray gun and
with my HVLP which uses compressor and turbo fan, I leave the
compressor at 110 as always and have a regulator on the gun. I don't
watch the exact setting on the gaugae I go by how it is spraying but I
think I usually run around 25-30 at the gun. I don't notice a drop.

If you are using a 1/4 or 3/8 hose you might want to grab a 1/2 hose
to add volume. At that distance it can make a difference.

On Thu, 17 Nov 2011 08:11:28 -0800 (PST), Robatoy
<[email protected]> wrote:

>> [email protected]
>
>Even if the job isn't very big, I'm a pot-fed kinda fella. (PUT those
>wisecracks away!!LOL)

Too easy! ;)


>So easy to adjust, sprays upside down. You can

How often do you find yourself hanging by your ankles to shoot a bit
of paint, sir? Inquiring minds, y'know...


>get the whole shebang for 60 bucks for a 2 litre.
>The cleaning is only a bit more work, and just the reduced fatigue in
>the spray arm alone is worth it. Currently, I own a couple of HVLP
>guns, a 2 litre pot and a 5qt floor pot. Nice lightweight hoses and a
>gravity fed HVLP with a 2 mil tip for thick stuff like Jay Cooke
>primer.

What do you use your guns for, Toy?


>I can kick my ass for selling my Iwata gun, but it has since been
>improved upon, but a bit spendy. http://www.danielsmith.com/Item--i-155-030-005

http://www.chicagoairbrushsupply.com/iwrg3mispgun.html Save $75 if
you haven't already bought one.

--
Most powerful is he who has himself in his own power.
-- Seneca

On Nov 19, 11:47=A0am, Larry Jaques <[email protected]>
wrote:
> On Fri, 18 Nov 2011 16:40:05 -0800 (PST), Robatoy
>
> <[email protected]> wrote:
> >On Nov 17, 10:21=A0pm, Larry Jaques <[email protected]>
> >wrote:
> >> >> What do you use your guns for, Toy?
>
> >What kind of stuff do I spray? A lot of Jay Cooke primer in my signs,
> >a lot of One-shot enamel in fades and back-grounds on those signs, the
> >odd piece of furniture, a quick refinish for an old couple's
> >kitchen... The rims on my kids car.... etc...
>
> "Stuff", got it. =A0Thanks.
>
> http://www.haradhesive.com/jay_cooke.html=A0Looks like good stuff.
> Expensive?
>
> --
> Most powerful is he who has himself in his own power.
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0-- Seneca

The bit of extra money per gallon, gets reimbursed by the serious
build-up. I'll look at my invoices, around mid- 30$
http://www.raycosignsupply.com/852

On Nov 19, 4:58=A0pm, "Mike Marlow" <[email protected]>
wrote:
> Robatoy wrote:
> > The bit of extra money per gallon, gets reimbursed by the serious
> > build-up. I'll look at my invoices, around mid- 30$
> >http://www.raycosignsupply.com/852
>
> Do you have any problems with shrinkage?
>


Only when I swim in cold water.
.
.
.
.
.
.
.
.
.
.
Come ON! Somebody had to say that.. Now. re paint...
No problem with shrinkage.

On Nov 16, 12:00=A0pm, chaniarts <[email protected]> wrote:

> however, when i start spraying, it drops down to the 20 psi
> range whilst i'm spraying, and going back up when i release the trigger.
>
> when i crank the pressure up at the compressor regulator, the pressure
> then, of course, goes up at the gun. when i start spraying, the pressure
> drops pretty quickly, then rises back up when stopping spraying.

Keep the pressure up at the compressor, just about at its limit. You
are going about it correctly by controlling the output to the gun with
a separate regulator at the gun handle. More compression behind the
gun will assure you that your compressor will not cycle as often as
low pressure.

I have a couple of those HF HVLP guns and they are surprisingly good.
I don't know your model (not that it would matter) but I usually find
the sweet spot for spraying at about 12 - 18 pounds at the gun. If
you are shooting at 40psi to the gun, no doubt you are draining your
compressor quickly. Remember, High Velocity, LOW Pressure.

If you can't get your material out at lower pressures, thin it out
more. When I was learning to shoot with a HVLP gun powered by a
compressor, I set it up like a high pressure gun. My compressor
couldn't keep up, I had lots of overspray and drift, and didn't see
any savings in material. After really woodshedding that gun and
getting some excellent advice, I got it to where I want it.

Remember, and HVLP setup will not atomize your finish material the way
an old fashioned high pressure spray will. It isn't designed to work
that way, hence, it simply won't.

> this is my first experience with an hvlp, so is this normal? is the
> 20psi during spraying good enough? it seems to be spraying a pretty fine
> mist at 20psi when i did my testing with plain water.

> what i'm spraying is mostly water anyway, so it shouldn't be too much
> different viscosity.

Shooting water shouldn't be a trick for any gun/compressor at any
pressure. Keep the pressure low, and adjust your feed and pressure as
needed to keep the water flowing.

Robert

Robatoy wrote:

> The bit of extra money per gallon, gets reimbursed by the serious
> build-up. I'll look at my invoices, around mid- 30$
> http://www.raycosignsupply.com/852

Do you have any problems with shrinkage?

--

-Mike-
[email protected]

chaniarts wrote:
> On 11/16/2011 12:36 PM, [email protected] wrote:

>
>> I have a couple of those HF HVLP guns and they are surprisingly good.
>> I don't know your model (not that it would matter) but I usually find
>> the sweet spot for spraying at about 12 - 18 pounds at the gun. If
>> you are shooting at 40psi to the gun, no doubt you are draining your
>> compressor quickly. Remember, High Velocity, LOW Pressure.
>
> this is the one i picked up
> <http://www.harborfreight.com/professional-automotive-hvlp-spray-gun-kit-94572.html>
>

I have recommended a lot of Harbor Freight guns to people over the years,
and some of their models are very good guns - especially for the price.
That said - I would not consider the model this link points to, to be and
HVLP gun. At 35-40 psi, this gun is in the league of the old siphon guns.
HVLP should be running under 20 psi. Depending on what I'm shooting in my
Devilibiss HVLP, I'm anywhere between 13 psi and 23 psi. You can't expect
to get ~10 psi at the cap if the input pressure gets too high. The guns are
not magic, and can only do so much in reducing the delivery pressure. At a
point, you're not really delivering HVLP anymore. Compare the material
useage and the overspray with that of an old siphon gun, and I'll bet you
don't see a lot of difference.

--

-Mike-
[email protected]

On Nov 17, 11:43=A0am, Larry Jaques <[email protected]>
wrote:
> On Thu, 17 Nov 2011 08:11:28 -0800 (PST), Robatoy
>
> <[email protected]> wrote:
> >> [email protected]
>
> >Even if the job isn't very big, I'm a pot-fed kinda fella. (PUT those
> >wisecracks away!!LOL)
>
> Too easy! =A0;)
>
> >So easy to adjust, sprays upside down. You can
>
> How often do you find yourself hanging by your ankles to shoot a bit
> of paint, sir? =A0Inquiring minds, y'know...
>
> >get the whole shebang for 60 bucks for a 2 litre.
> >The cleaning is only a bit more work, and just the reduced fatigue in
> >the spray arm alone is worth it. Currently, I own a couple of HVLP
> >guns, a 2 litre pot and a 5qt floor pot. Nice lightweight hoses and a
> >gravity fed HVLP with a 2 mil tip for thick stuff like Jay Cooke
> >primer.
>
> What do you use your guns for, Toy?
>
> >I can kick my ass for selling my Iwata gun, but it has since been
> >improved upon, but a bit spendy.http://www.danielsmith.com/Item--i-155-0=
30-005
>
> http://www.chicagoairbrushsupply.com/iwrg3mispgun.html=A0Save $75 if
> you haven't already bought one.
>
nice CATCH!!! Thankee kindly, Sir! I will order.

On Nov 17, 10:26=A0am, "Mike Marlow" <[email protected]>
wrote:
> chaniarts wrote:
> > On 11/16/2011 12:36 PM, [email protected] wrote:
>
> >> I have a couple of those HF HVLP guns and they are surprisingly good.
> >> I don't know your model (not that it would matter) but I usually find
> >> the sweet spot for spraying at about 12 - 18 pounds at the gun. =A0If
> >> you are shooting at 40psi to the gun, no doubt you are draining your
> >> compressor quickly. =A0Remember, High Velocity, LOW Pressure.
>
> > this is the one i picked up
> > <http://www.harborfreight.com/professional-automotive-hvlp-spray-gun-k.=
..>
>
> I have recommended a lot of Harbor Freight guns to people over the years,
> and some of their models are very good guns - especially for the price.
> That said - I would not consider the model this link points to, to be and
> HVLP gun. =A0At 35-40 psi, this gun is in the league of the old siphon gu=
ns.
> HVLP should be running under 20 psi. =A0Depending on what I'm shooting in=
my
> Devilibiss HVLP, I'm anywhere between 13 psi and 23 psi. =A0You can't exp=
ect
> to get ~10 psi at the cap if the input pressure gets too high. =A0The gun=
s are
> not magic, and can only do so much in reducing the delivery pressure. =A0=
At a
> point, you're not really delivering HVLP anymore. =A0Compare the material
> useage and the overspray with that of an old siphon gun, and I'll bet you
> don't see a lot of difference.
>
> --
>
> -Mike-
> [email protected]

Even if the job isn't very big, I'm a pot-fed kinda fella. (PUT those
wisecracks away!!LOL) So easy to adjust, sprays upside down. You can
get the whole shebang for 60 bucks for a 2 litre.
The cleaning is only a bit more work, and just the reduced fatigue in
the spray arm alone is worth it. Currently, I own a couple of HVLP
guns, a 2 litre pot and a 5qt floor pot. Nice lightweight hoses and a
gravity fed HVLP with a 2 mil tip for thick stuff like Jay Cooke
primer.
I can kick my ass for selling my Iwata gun, but it has since been
improved upon, but a bit spendy. http://www.danielsmith.com/Item--i-155-030=
-005

On 11/16/2011 12:36 PM, [email protected] wrote:
> On Nov 16, 12:00 pm, chaniarts<[email protected]> wrote:
>
>> however, when i start spraying, it drops down to the 20 psi
>> range whilst i'm spraying, and going back up when i release the trigger.
>>
>> when i crank the pressure up at the compressor regulator, the pressure
>> then, of course, goes up at the gun. when i start spraying, the pressure
>> drops pretty quickly, then rises back up when stopping spraying.
>
> Keep the pressure up at the compressor, just about at its limit. You
> are going about it correctly by controlling the output to the gun with
> a separate regulator at the gun handle. More compression behind the
> gun will assure you that your compressor will not cycle as often as
> low pressure.

it's usually used for sandblasting, so is a large tank and relatively
large pump. i ran a test for about 15 minutes with plain water, and it
never kicked on to refill. the tank fills to 125psi but the regulator
there is normally set to 75 for blasting.

> I have a couple of those HF HVLP guns and they are surprisingly good.
> I don't know your model (not that it would matter) but I usually find
> the sweet spot for spraying at about 12 - 18 pounds at the gun. If
> you are shooting at 40psi to the gun, no doubt you are draining your
> compressor quickly. Remember, High Velocity, LOW Pressure.

this is the one i picked up
<http://www.harborfreight.com/professional-automotive-hvlp-spray-gun-kit-94572.html>

>
> If you can't get your material out at lower pressures, thin it out
> more. When I was learning to shoot with a HVLP gun powered by a
> compressor, I set it up like a high pressure gun. My compressor
> couldn't keep up, I had lots of overspray and drift, and didn't see
> any savings in material. After really woodshedding that gun and
> getting some excellent advice, I got it to where I want it.

it's probably 98% water, so i doubt that it can be thinned more. the
product is the liquid that is in Scotchguard rattle cans purchased in
bulk. i'm spraying a lot of furniture.

> Remember, and HVLP setup will not atomize your finish material the way
> an old fashioned high pressure spray will. It isn't designed to work
> that way, hence, it simply won't.
>
>> this is my first experience with an hvlp, so is this normal? is the
>> 20psi during spraying good enough? it seems to be spraying a pretty fine
>> mist at 20psi when i did my testing with plain water.
>
>> what i'm spraying is mostly water anyway, so it shouldn't be too much
>> different viscosity.
>
> Shooting water shouldn't be a trick for any gun/compressor at any
> pressure. Keep the pressure low, and adjust your feed and pressure as
> needed to keep the water flowing.
>
> Robert

thanks for the help all.

On Thu, 17 Nov 2011 16:33:13 -0800 (PST), Robatoy
<[email protected]> wrote:

>On Nov 17, 11:43 am, Larry Jaques <[email protected]>
>wrote:
>> On Thu, 17 Nov 2011 08:11:28 -0800 (PST), Robatoy
>>
>> <[email protected]> wrote:
>> >> [email protected]
>>
>> >Even if the job isn't very big, I'm a pot-fed kinda fella. (PUT those
>> >wisecracks away!!LOL)
>>
>> Too easy!  ;)
>>
>> >So easy to adjust, sprays upside down. You can
>>
>> How often do you find yourself hanging by your ankles to shoot a bit
>> of paint, sir?  Inquiring minds, y'know...
>>
>> >get the whole shebang for 60 bucks for a 2 litre.
>> >The cleaning is only a bit more work, and just the reduced fatigue in
>> >the spray arm alone is worth it. Currently, I own a couple of HVLP
>> >guns, a 2 litre pot and a 5qt floor pot. Nice lightweight hoses and a
>> >gravity fed HVLP with a 2 mil tip for thick stuff like Jay Cooke
>> >primer.
>>
>> What do you use your guns for, Toy?

Hiding your use, eh?



>> >I can kick my ass for selling my Iwata gun, but it has since been
>> >improved upon, but a bit spendy.http://www.danielsmith.com/Item--i-155-030-005
>>
>> http://www.chicagoairbrushsupply.com/iwrg3mispgun.html Save $75 if
>> you haven't already bought one.
>>
>nice CATCH!!! Thankee kindly, Sir! I will order.

Jewelcome.

--
Most powerful is he who has himself in his own power.
-- Seneca