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Airless or compressor?


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#1 DrWatson

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Posted 25 April 2019 - 01:24 AM

One of the things I despise is painting. For me, painting is best done with a bottle of red wine, brushes, pallet knives, tubes of oils and canvass.

 

When faced with anything else that needs painting, I’m prone to procrastination. Unfortunately, I foresee a considerable number of painting related tasks in my future. As I’m also a tight bugger and have philosophical issues with paying someone to do a job I can do if I try, and also so that I might actually achieve some of those tasks and finish them before I’m in my grave, I’m considering getting a spray painting setup. I reason that apart from the initial fun of a new “toy”, which will hopefully get me through the current list of jobs, in the long run such a device will undoubtedly save me time and money with respect to bottom paint, to name just one item.

 

 

 

My question is: Airless or air compressor fed system?

 

 

 

I have access to a compressor. What are the advantages/disadvantages of each one? I honestly know slightly more than nothing about them.

 


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#2 Frank

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Posted 25 April 2019 - 05:50 AM

What objects/surfaces you proposing to paint ? and what sort of paints, e.g  two pack systems ? My experience with early wagner airless DIY units and two pack paints was not good. So  unless modern designs have improved dramatically I would go compressor driven. I have a small gravity fed $50 touch up gun and a $200 direct drive compressor I use it a lot for small jobs where I want a good finish. Mostly these are objects I can take off the boat and paint at home. Belt driven units are better but more expensive and still wont deliver the flow for painting a hull, or at least that is what my boat painter friend says. So if you have that in mind then your Scottish side wont like  it as you will need a 3 phase or petrol driven compressor. 

You need to thin the paint more for small compressors, its a bit trial and error to get it right. When I spray using water based paints I thin with Bars Bugs Window wash concentrate (trust me it works :-)  

As with all painting a good result is prep and technique dependent I would practice with small jobs and cheap paint, Good luck !

 

Edit: Re airless units,  my comments do not include professional/ industrial airless rigs used to paint houses etc, but then they cost thousands I imagine.


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#3 Priscilla II

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Posted 25 April 2019 - 07:09 AM

If you are looking to spray your house, roof, fence or any large area using acrylic the airless is the only option.
If you are spraying anti foul, epoxy tar or products like Interprotect the airless is the only option.
For hull topsides ,2 pack applications ,enamels and smaller areas and stuff gravity feed spray guns with a compressor are the only option.
Gun tip size is critical for best finish with both systems.
A water trap for compressor spraying is essential.
My professional painter does interior doors to a excellent finish using airless and enamel paint but he is a professional.
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#4 Knot Me... maybe

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Posted 25 April 2019 - 08:31 AM

Go to spray painting equipment shop.

Ask 'I have zero experience but are keen to give it a go, what would you suggest for a 2nd year spray painting apprentice?'

Buy what they recommend.

Find a boat

Prep it well

Mix some paint.

get out the gun and go hard.

CLEAN gun well afterwards.

 

I got a gun with a 600ml hopper on top that hooks to a compressor.

 

I'm building Bayswatervail, like Gloriavale but without the bad touching and silly names, so have a few ply clad buildings in the backyard. Filled the gun with water and played on of the structures which is still bare ply. Doing that I got to play with the knobs to see what they do, that was handy. I fiddled and then took a punt where to set things and went for it.

 

One thing I did learn about but didn't have really have a chance to play with is what Priscilla rightly mentions, the tip size can be a make or break item. The gun came with a 2mm I think it was, which luckily did suit the style of paint I was using. It was suggested I use a slightly smaller one which would give me a little more control for the smaller area, the topsides, I was doing.

 

That's what I did and while there is the odd flaw and I did need to redo the last coat (after following some professional advice which was wrong) it's come up surprisingly good. The bonus is now I have a gun and enough knowledge to have the family shitting itself I'm about to start repainting the house, cars, other boats and Lipton the cat.


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#5 wheels

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Posted 26 April 2019 - 06:00 PM

It's not quite as straight forward as it sounds.
If you want to spray on AF, you can only do that with High pressure airless. It goes on real quick and a small Hull would not warrant to cost of equipment, the speed it applies at and the thinners required for the clean up at the end.
You cannot spray AF without thinning and you must not thin AF.

For top coats, air would be best for small boats up to say 35ft. Airless once again, is used on very large area's.
The benefit of roll and brush is that you do not need thinners, which is a saving and if you are using two pot paints, it tends to be far safer to apply. If you spray, you need all sorts of safety gear and you need to think about where over spray may go. And yep, you lose about 10% of paint to over spray. Possibly a lot more if you are not experienced.

A 2mm nozzle will be far too big for a beginner. It throws the paint at the surface. 2mm is usually used for high build products.

Forget the Wagner home handyman airless machines. IMO, they don't produce a nice finish.


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#6 Crazyhorse

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Posted 27 April 2019 - 07:25 AM




It's not quite as straight forward as it sounds.
If you want to spray on AF, you can only do that with High pressure airless. It goes on real quick and a small Hull would not warrant to cost of equipment, the speed it applies at and the thinners required for the clean up at the end.
You cannot spray AF without thinning and you must not thin AF.

For top coats, air would be best for small boats up to say 35ft. Airless once again, is used on very large area's.
The benefit of roll and brush is that you do not need thinners, which is a saving and if you are using two pot paints, it tends to be far safer to apply. If you spray, you need all sorts of safety gear and you need to think about where over spray may go. And yep, you lose about 10% of paint to over spray. Possibly a lot more if you are not experienced.

A 2mm nozzle will be far too big for a beginner. It throws the paint at the surface. 2mm is usually used for high build products.

Forget the Wagner home handyman airless machines. IMO, they don't produce a nice finish.


Not heard that? Or do you mean "should" not thin AF?

(DESCRIPTION

Designed to reduce the viscoity of all antifouling paints (excluding Micron Optima and VC products). Highly recommended if you want to get the perfect viscosity of your antifouling paint for a smooth and even application. Can be used with the spraying application of one-part varnishes.

For thinning antifouling paints)
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#7 Knot Me... maybe

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Posted 27 April 2019 - 09:53 AM

What sort is this?

Airless or un-airless (hope I'm not getting to deep in techno jargon there :) )

 

Attached File  index.jpg   3.02KB   0 downloads

 

Mine has a 1.4 tip, not the 2 I thought it was. 

 

 


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#8 Island Time

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Posted 27 April 2019 - 11:13 AM

Air, but might be standard or HVLP

HVLP - High Volume Low pressure. Great Guns, very little overspray.
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There is nothing, absolutely nothing, half so much worth doing, as simply messing about in boats


#9 lateral

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Posted 27 April 2019 - 01:07 PM

Sprayed the bulkheads inside of my boat, head etc with 2pac international,  plus deck in places.

Do-able if you're a flagellist.

As 2pac are generally isocyanate containing, breathing apparatus + extraction essential.

16cuft compressor.HVLP, Devilbiss gun, pressure pot & 2.3mm tip & gravity /1.3mm tip for topcoat

Separate positive air to full face air supply. peel off vision film. 2x pressure /volume control.

 

Prep is everything.

Hi-build,

fair

More Hi-build 

supa fair

Microsurfacer

Supa x supa fair

320 grit minimum

Tack cloth 

Prepsol

100 white clean rags later

Tie coat/primer

Light topcoat....wait with consideration to humidity, temp, amount of thinners, type of thinners, retarders , strainers etc

peel one edge tape.

Heavy coat with attention to above constraints & having exorcised sag demons lurking nearby.

peel last edge tape while it can still "round off"

Go away and pray.

Come back and be: 

Smug by your management of the variables and  admit you are a painting genius

Or go into soul searching mode as to wtf you didn't see/why  the, orange peel, non-uniformity, lack of/change of gloss,

UFO's imbedded, sags,fish-eyes, and the myriad of other pitfalls of 2pac/ any pac painting.

 

Easier do do what you normally do and pay a pro OC specialist marine/car painter.

BTW car paint is easier to use.

 

Sprayed my Jarrah kitchen bench with 2pac clear over flowcoat epoxy, and kept the other half happy.

Pretty damn good is the feedback I get.

Perfection is an illusion, unless you have unlimited time & money.

 

Would I do it again? There's always roll & tip.


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#10 wheels

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Posted 28 April 2019 - 06:21 AM

"Not heard that? Or do you mean "should" not thin AF?"

 

If you read the info on the AF you are going to apply, it will, or should say "DO NOT THIN". AF is not just a paint film. It is a complex "sponge" holding all the things required to make it work properly. Thinners will change how that coating works.

 

 

What sort is this?

Airless or un-airless (hope I'm not getting to deep in techno jargon there :) )

It's an over head gravity fed cup, compressed air fed. They are good for delivering heavier coatings because the paint drops down by gravity into the Airflow. Gus that have the cup underneath work by Venturi and suck the Paint up and are thus called, Suction Cup fed.
 

 

HVLP - High Volume Low pressure. Great Guns, very little overspray.

HVLP or High volume low pressure work by a large hose with an air pump more like a vacuum cleaner motor moving a large volume of air at very low pressure. They don't produce as much overspray. But you have to use three times more thinners to make it work and it does not allow for a high build of film because of that.

Airless are large systems. They are more like a waterblaster in that they have a very highpressure pump that blows the coating on without the need of any air what so ever.

Lateral, next time you want to get that real deep high gloss finish, try using Doming Resin. It's a very clear Polyester Resin that you pour on. You then get a propane torch and with a very low flame, you quickly brush the flame over the coating and all the little airbubbles pop to the surface and burst. Leaves a crystal clear finish. Doming resin is that they encapsulate Insects in for display. Like you may have seen with say a Scorpian inside a globe of resin.


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