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Airless or compressor?


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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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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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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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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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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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"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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DrWatson, what are you spraying,if a boat in haulout yard there are restrictions,whether it be airless or air. fully enclosed tents seem to be the option nowdays,antifoul found good using airless and just thinned enough to come out of gun,4lts gave 3 even coats on a D28 recently. 

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Depends on the antifoul. Why would companies produce "thinners for antifoul"!!!? Petit actually advises thinning.

Yes it sure does depend on AF. And I should have said, Read the Instructions. Most AF's say no thinning.

There is also a big difference between thinning for applying on a Hot day by Roller and thinning for Spray Painting. Even for Petit, it should read that there is a maximum thinning rate. I think it is no more than 10%. Where as to thin for Air Spray application, you need to be closer to 30% or even more. Plus when you thin, you obviously have a thinner film thickness, so you need far more coats than normal. Most AF's work on a minimum of two coats unthinned to get the required film thickness. High pressure spray due to being able to be apply with no thinners, means you can often get the correct thickness with the one application. The first blow over has dried enough to allow a second coat wet on wet but not cause run. Thinning causes increases dry time.

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No, it is definitely Polyester. Epoxy would also do the jo if you have a lovely clear one. The only difference is getting the air bubbles out. You must use the blow torch to do so on the Polyester.
Another way of removing bubbles from these, or any liquid for that matter, is to place the mix in a vacuum. Even if it is just a Vacuum cleaner. The low pressure causes the bubbles to increase in size and float to the surface. Once all bubbles are gone, then release the vacuum and anything that was too small to raise should disappear.

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DrWatson, what are you spraying, if a boat in haulout yard there are restrictions, whether it be airless or air. fully enclosed tents seem to be the option nowdays, antifoul found good using airless and just thinned enough to come out of gun, 4lts gave 3 even coats on a D28 recently. 

Well, looking to do a bit of everything. I make a few small dinghies etc, so looking to paint those, but that is done in the shop. The antifouling is one thing I was looking to use it for - but the options here seem less likely. 

 

I don't mind tenting my boat in a yard, thats not a bad idea at any time and is also a reasonable courtesy if you're doing paint work. Vacuum sanding (or wet?) is also the norm, as I understand it. 

 

Wheels, is there a difference between hard and ablative antifoul regarding "sprayability"? I don't know exactly what is on our boat at the moment. I only know that if cost €350 more to get the cool orange rudders because they had to clean all the equipment out (normally grey) to do it just for our job. Also, the orange is apparently vastly inferior as an antifoul...

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 bright orange antifoul is likely Petit Vivid. I could be wrong, but that is the only AF I know that has bright colors. It is real expensive and good for Boot topping, but not the greatest performer IMO.
The only AF I have come cross that was thin enough to spray was Hempels, Real easy to roll on too.

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bright orange antifoul is likely Petit Vivid. I could be wrong, but that is the only AF I know that has bright colors. It is real expensive and good for Boot topping, but not the greatest performer IMO.

The only AF I have come cross that was thin enough to spray was Hempels, Real easy to roll on too.

Was given "vivid" last year so tried it, garbage! No copper as its for alloy hulls so has some other biocide in it and loads of barnies after only 6 months.

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Was given "vivid" last year so tried it, garbage! No copper as its for alloy hulls so has some other biocide in it and loads of barnies after only 6 months.

I use Vivid, you just need to clean it- Barnies release easy but it’s not designed for people who want to ignore the underside of their boat. As a bottom paint that is regularly cleaned it’s great easy to clean and lasts a season.

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I also had a great run with Vivid on my 830, in the Weiti and cleaning regularly for racing.

I’ve just applied the same to the 930, by airless.

2 full coats all over and a third on the waterline, bow sections and foils.

Went back in a month ago, haven’t cleaned yet but a thin brown coat of slime evident top 100mm. Wipes clean with ease so hopefully will slide off when we motor out for the Enduro????

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