low cost HVLP gun for clearcoat?

[Isaac-1]

I am looking at trying my hand at an automotive paint repair, a couple of months ago I bought a 15 year old 28 ft long motorhome, which has aluminum sides and roof with fiberglass end caps. It has a few paint issues, including some rather amatuerish repairs with poor paint matches, but overall is in very good shape for its age. I plan on getting the paint issues that are more glaringly visible professionally painted, specifically a couple of paint mismatch spots on the corner of the bumper and a 3x3 ft area below the front passenger window which is not even close to matching.

The issue I am thinking about trying to repair myself, is the failing clearcoat near the roof above the built in aluminum gutter. This is about a hand width section of siding where it curves over to meet the roof that runs the length of the coach. The clearcoat here is still mostly intact and is starting to peel in spots along the passenger side (on the driver side there are just a few pin holes and small blisters), lets say it is still 85-90% intact. My plan it to lightly wet sand this section above the gutter then spray a modern clearcoat with activator down the full length. I know the end result will not be perfect, but I hope it will be good enough keeping in mind this location is hard to see from the ground as it is at about the 10 ft level and rounded upward.

I have a shop building that the motorhome will fit in barely, a lift, PAPR OV respirator, DA polisher / sander and a decent shop air compressor I forget the exact specs, but it is about 6 ft tall and retailed for about $1,200.

What I need advice on is what would be an acceptable HVLP gun tip size and type, cup size, etc. Keeping in mind that the result will never be seen close up. Also keeping in mind that the surface to be painted is a pair of horizontal sections roughly 27 ft long and and 6 inches top to bottom that curves from horizontal to vertical. Specific brands and models would be great, also are the Harbor Freight grade HVLP guns good enough for such a project?

thanks

 

[jloehlein]

I have the "nice" Harbor Freight gun (this one). I've only sprayed one car with it, but it came out well. I had to experiment with the gun settings, air pressure, and my technique, but the panels I did well didn't need any wet sanding or buffing when I was done. For your purposes, it should be fine.

Pay attention to your air system, too. I use the shortest 1/2" hose with high flow 3/8" couplers and this filter dryer.

I'd pick your clearcoat before doing the prep - it will come with instructions. Do some research on clearcoat repairs and ask the paint shop for their advice, too. You may just need to scuff it to a matte finish with grey scotchbrite to get the new stuff to adhere.

 

[Tunajoe]

I'll second the HF gun.
I actually use the purple one which is less money. Works pretty damn good

 

[fastbike02]

I love the purple HF guns, they spray great and and can be had for 10 bucks!

 

[fastbike02]

some of the paint jobs I've done with the cheap gun


I have more but I hate trying to upload to photobucket

 

[Tim37]

The hf gun is ok. The reason body shops use the expensive guns is so they can match a factory finish. On something like a motor home where a little extra orange peal isn't going to attract attention or something that is going to need sanded and buffed any such as a show car the hf gun works great and doesnt break the bank.

 

[dogdog]

HF $50 one is ok, what ever you get make sure your compressor can meet the CFM requirement and AIR line and coupling are matching the flow, plus filters for moistures..... I got a lot of fish eyes spraying in the cold.


I think eastwood also sells a version of that HVLP gun that works with smaller compressors.

 

[dnschmidt]

These threads always make me laugh. The cost of quality automotive paint is astronomical and you want to shoot this stuff with a $50 spray gun and a 2HP compressor. Oh well, this madness can wait for another day but with respect to cheap spray guns there is only one way to go and that's Astro Pneumatic. For around $100 you can get something that actually does produce a great finish. I would recommend the Euro Blue gun (RP type) in 1.3mm.

I have 37 SATA guns, 18 DeVilbiss guns, 9 Iwata guns and 6 Sharpe guns (before Graco bought them and screwed them up - the Titanium was a really good gun). Along with these I have about 30 Astro guns in both Mini and Full size models and for the money Astro's guns (made by a really great company in Taiwan: Rich Star Precision Industries) are the best on the market by far.

AND YEA, I REALLY, REALLY, REALLY LIKE SPRAY GUNS.

 

[dogdog]

These threads always make me laugh. The cost of quality automotive paint is astronomical and you want to shoot this stuff with a $50 spray gun and a 2HP compressor. Oh well, this madness can wait for another day but with respect to cheap spray guns there is only one way to go and that's Astro Pneumatic. For around $100 you can get something that actually does produce a great finish. I would recommend the Euro Blue gun (RP type) in 1.3mm.

I have 37 SATA guns, 18 DeVilbiss guns, 9 Iwata guns and 6 Sharpe guns (before Graco bought them and screwed them up - the Titanium was a really good gun). Along with these I have about 30 Astro guns in both Mini and Full size models and for the money Astro's guns (made by a really great company in Taiwan: Rich Star Precision Industries) are the best on the market by far.

AND YEA, I REALLY, REALLY, REALLY LIKE SPRAY GUNS.

Not every one operates a 1000 HP compressor at home ..... would be nice and I wouldn't mind spending few hundred on the spray gun.... actually I do have the devilbiss finishline series gun, but without the 100000 HP compressor to drive it and the GIG watt dehumidifier to remove water, it spray like ****.

 

[johninct]

If I understand what you want to do, flake off all of the loose clear coat, scuff everything up and re-clear everything, there are some problems. You will see where the flaked off clear was but I understand that in your case it won't matter. The big problem can be when you clear over everything the remaining clear edges may lift.

 

[dnschmidt]

Wait a minute. I have a lowly Quincy 5 HP 17 cfm double stage at home and it get's the job done. WHERE CAN I BUY A 1000HP COMPRESSOR? Just added something to my Christmas list. The Finishline 3 (and if you live in Europe or Asia they now have a Finishline 4 which is even better) are really decent for the price.

Water, what water? I live in Phoenix, AZ dude. Water? It's rained today for the first time in three months. When I drain the water from my compressor after a week I might get three ounces of water out of it.

 

[Isaac-1]

Thank for all the replies, does anyone have a suggestion of tip size of gun type as it relates to the size and shape of the job. I assume a 28 ft long by 6 inch wide swath is not a typical job and for practical matters of working on a lift or scaffolding will have to be done in sections. I would plan on masking off and running plastic dropcloth down the full length Aluminum gutter (about finger width) and then just spray to the roof transition, the roof is white finish automotive paint on Aluminum roof, but also has seam sealing tape,and all the usual vents, solar panels, and other openings so is already not the most attractive of areas, but thankfully can only be seen from above. Would a lower CFM detail gun work better?

 

[bsaint]

Im not sure about which gun, but Ive been told of all the guns to skimp on - the clearcoat one is not the one to do with with. Just what Ive heard.

 

[Lhorn]

Agree with dnschmidt. Astro makes a real nice gun for around $100

 

[94EG8]

The hf gun is ok. The reason body shops use the expensive guns is so they can match a factory finish. On something like a motor home where a little extra orange peal isn't going to attract attention or something that is going to need sanded and buffed any such as a show car the hf gun works great and doesnt break the bank.

That's a little truth in there. The biggest reason shops use expensive guns is for a wide spray pattern so you can put more paint on in each pass. A cheap gun may have a 6" fan, a nice SATA will have something a lot wider, say 12". It does help for matching a factory finish as well, which these days usually means you actually need a little texture.

These threads always make me laugh. The cost of quality automotive paint is astronomical and you want to shoot this stuff with a $50 spray gun and a 2HP compressor. Oh well, this madness can wait for another day but with respect to cheap spray guns there is only one way to go and that's Astro Pneumatic. For around $100 you can get something that actually does produce a great finish. I would recommend the Euro Blue gun (RP type) in 1.3mm.

This ^ The paint is what really costs, and it costs every time you do a project. The gun you buy once for the average home user (if you buy a good one) and it will last a long time.

I have 37 SATA guns, 18 DeVilbiss guns, 9 Iwata guns and 6 Sharpe guns (before Graco bought them and screwed them up - the Titanium was a really good gun). Along with these I have about 30 Astro guns in both Mini and Full size models and for the money Astro's guns (made by a really great company in Taiwan: Rich Star Precision Industries) are the best on the market by far.

AND YEA, I REALLY, REALLY, REALLY LIKE SPRAY GUNS.

Dude, what are you spraying?! I work for a large collision shop, we've got about half a dozen SATA guns for base/clear and a few Pro-Tek 4000s (Canadian rebranded offshore guns that actually work pretty well) for primer, epoxy, etc. I can't see the need for that many guns even in a very large shop.

Not every one operates a 1000 HP compressor at home ..... would be nice and I wouldn't mind spending few hundred on the spray gun.... actually I do have the devilbiss finishline series gun, but without the 100000 HP compressor to drive it and the GIG watt dehumidifier to remove water, it spray like ****.

You don't need anything crazy, if you're doing partial jobs then a cheap 3hp single stage with a 60 gallon tank will do (I've see guys get by with less) For completes I'd recommend a 5hp, 2 stage. Since I have done this before, and recently at that I'll break it down. I spent $650 on a used 5hp, 60 gallon 2 stage compressor, $200 on a used Zeks aftercooler and $12 on a Princess Auto Powerfist water separator. That's not an extreme amount of money. I went with a Pro-Tek 4000 gun, they run about $175 here in Canada, you can get a decent finish out of them, but nothing like a SATA.

Thank for all the replies, does anyone have a suggestion of tip size of gun type as it relates to the size and shape of the job. I assume a 28 ft long by 6 inch wide swath is not a typical job and for practical matters of working on a lift or scaffolding will have to be done in sections. I would plan on masking off and running plastic dropcloth down the full length Aluminum gutter (about finger width) and then just spray to the roof transition, the roof is white finish automotive paint on Aluminum roof, but also has seam sealing tape,and all the usual vents, solar panels, and other openings so is already not the most attractive of areas, but thankfully can only be seen from above. Would a lower CFM detail gun work better?

The size of the job has nothing to do with tip size. Tip size is determined based on the product being sprayed. Generally for clear a 1.3 - 1.4mm tip is used.

If you're stopping and starting you're going to see where you stopped and started spraying again. You may need to use a spray blending agent. I'd also recommend it for blending the new clear into the old.

 

[dnschmidt]

94EG8, I spray restorations primarily but that has nothing to do with my extensive spray gun collection. I just really like spray guns. For a time I was a part of DeVilbiss' beta testing team so I got several Tekna's for free for participating in the study and providing DeVilbiss with feedback. I believe my small contribution, along with that of the other members of the team, several of which are very well known, contributed to the home run that the Tekna Prolite turned out to be. Need has nothing to do with having a Jones for spray guns. Many Americans collect gun guns. I collect spray guns.

 

[Lhorn]

Eastwood has a line of guns that supposedly use much less air. Can't vouch for how they spray but not too $$$. Might be worth a try. Sharpe use to make one too that was considered a good gun and easy on air consumption. Not sure if they make it anymore or not.

The Eastwood gun: $57 currently

Concours LT HVLP
Details
Professional quality painting with a home shop compressor.

Professional quality painting from a home compressor
Low CFM – requires just 4CFM @ 30PSI
Great atomization & wide spray pattern
1.3mm base coat/clear coat nozzle included
Compatible with all types of coatings
Stainless internal passages & brass air cap
1.5mm, 1.7mm, and 2.0mm nozzles available
The Eastwood Concours LT HVLP paint gun has many features of the professional guns, but it was specially designed to require the least amount of air possible. This makes it ideal for the home user without a big 80 gallon compressor. The aluminum body is anodized to resist corrosion, and all the internal passages are stainless steel for use with solvent or water based paints. Engineered specifically for great atomization and a wide spray pattern with high transfer efficiency and little overspray. A brass machined aircap is includes as well as a 1.3mm nozzle ideal for base coats or clear coats. Additional nozzles available in 1.5mm (#15641), 1.7mm (#15642) and 2.0mm (#15643) sizes. Gun comes complete with plastic cup and cleaning kit.

 

[Lhorn]

Looks like the HF guns vary in how much air they use. The nicer ones seem to be air hogs 12-15 cfm. The purple guns can run on as low as 6 cfm (at 40 psi). If you have a small compressor, I'd factor that in. The only thing that'll spray crappier than a cheap gun is a cheap gun meant to run on way more air than you have. The eastwood gun says 4 cfm at 30 psi.

 

[dnschmidt]

Lhorn the Sharpe gun that you are referring to was the Platinum. For a pro these were really slow for an amateur they were great since they didn't let you get into too much trouble. Prior to Graco buying them Sharpe made very nice spray guns for cheaper than average money. The Titanium was really nice.

 

[PBCampbell]

The size of the job has nothing to do with tip size. Tip size is determined based on the product being sprayed. Generally for clear a 1.3 - 1.4mm tip is used.

Okay, now explain how panel guns work with tip sizes recommended that are considerably smaller than full size guns for the same products. I am genuinely curious.

 

[dogdog]

Not every one operates a 1000 HP compressor at home ..... would be nice and I wouldn't mind spending few hundred on the spray gun.... actually I do have the devilbiss finishline series gun, but without the 100000 HP compressor to drive it and the GIG watt dehumidifier to remove water, it spray like ****.

.........

You don't need anything crazy, if you're doing partial jobs then a cheap 3hp single stage with a 60 gallon tank will do (I've see guys get by with less) For completes I'd recommend a 5hp, 2 stage. Since I have done this before, and recently at that I'll break it down. I spent $650 on a used 5hp, 60 gallon 2 stage compressor, $200 on a used Zeks aftercooler and $12 on a Princess Auto Powerfist water separator. That's not an extreme amount of money. I went with a Pro-Tek 4000 gun, they run about $175 here in Canada, you can get a decent finish out of them, but nothing like a SATA.
..

Just getting his knockers hardened..... LOL... the point was buy what you needed and there are other equipment also be considered. There are more other things needed to be considered on those fancier gun... is what I mean.... bigger air flow couplings, larger hose, air driers etc. I would just consider a lower CFM requirement gun if it is something I don't do every day. what I mean was that HF and Eastwood one have a lower CFM requirement and personally the HF spray decent for some one that does it once in a blue moon / not professionally.

 

[dnschmidt]

PBCampbell, the size of tip is primarily determined by the viscosity of the paint. Normally reduced clearcoats have about a 14 second time in a Zahn #2 cup. For a full size gun these would normally be sprayed with a 1.3 or 1.4mm nozzle. If it's a SATA you can do it with a 1.2mm since SATA lies about the size of their fluid tips. A full size gun, if it's worth a damn, has at least a 12" fan.

The MiniJet was invented by SATA and copied by everybody. These typically have either 0.8, 1.0 or 1.2 nozzles. The reason they can use these smaller sizes is that their fans are typically less than six inches at working distance. What that means is less paint is needed to fill the smaller fan than is required to fill the larger fan. That's why you can get by with the smaller nozzle.

Large tip sizes are needed on full size guns when the material is thicker. For example typical 2K primer uses a 1.8mm nozzle and polyester primer can use nozzles as big as 3mm. Airbrushes use paint that has been highly thinned in order to get it to flow through their quite small nozzles.

Normally, what determines nozzle selection is viscosity.

 

[DanielC99]

PBCampbell, the size of tip is primarily determined by the viscosity of the paint. Normally reduced clearcoats have about a 14 second time in a Zahn #2 cup. For a full size gun these would normally be sprayed with a 1.3 or 1.4mm nozzle. If it's a SATA you can do it with a 1.2mm since SATA lies about the size of their fluid tips. A full size gun, if it's worth a damn, has at least a 12" fan.

The MiniJet was invented by SATA and copied by everybody. These typically have either 0.8, 1.0 or 1.2 nozzles. The reason they can use these smaller sizes is that their fans are typically less than six inches at working distance. What that means is less paint is needed to fill the smaller fan than is required to fill the larger fan. That's why you can get by with the smaller nozzle.

Large tip sizes are needed on full size guns when the material is thicker. For example typical 2K primer uses a 1.8mm nozzle and polyester primer can use nozzles as big as 3mm. Airbrushes use paint that has been highly thinned in order to get it to flow through their quite small nozzles.

Normally, what determines nozzle selection is viscosity.

Yep, believe what Mr. dnschmidt says. ^^^^^^^^

"Normally, what determines nozzle selection is viscosity".

How many know what a #2 Zahn cup is and how it is used?

 

[minytrker]

I bought a set of 3 DeVilbiss guns several years ago pretty cheap online brand new. In the end you can either paint or you cant. I could paint the same with the DeVibiss guns as I could with my HF guns BUT I am not a professional painter. I did win best of show with some of my paint jobs to give you an idea of the quality.

 

[Isaac-1]

This is all interesting, but do I need a 12 inch fan if I am painting something that is roughly 6 - 8 inches tall and curved and 27 ft long? As to my compressor, I think it is a 60 gallon tank, and know it is a 2 stage with 240V motor I think 5HP, but may be 3HP, I just don't remember the CFM spec at the moment. I meant to look at it today, but forgot, I will try to in the morning if it is not raining. Hose length should not be an issue since the compressor sits about 5 ft from the front passenger corner of where the motorhome would be parked.

 

[RV8guy]

This is all interesting, but do I need a 12 inch fan if I am painting something that is roughly 6 - 8 inches tall and curved and 27 ft long? As to my compressor, I think it is a 60 gallon tank, and know it is a 2 stage with 240V motor I think 5HP, but may be 3HP, I just don't remember the CFM spec at the moment. I meant to look at it today, but forgot, I will try to in the morning if it is not raining. Hose length should not be an issue since the compressor sits about 5 ft from the front passenger corner of where the motorhome would be parked.

Here are two nice budget spray guns.

https://www.spraygunsdirect.co.uk/i...5-compliant-solvent-spraygun-best-seller.html

https://www.spraygunsdirect.co.uk/index.php/ani-full-sized-conventional-gravity-spraygun.html


They will both spray circles around the HF guns.

I've sprayed with a 5hp 30 gallon compressor and got good results. If yours is a little undersized then you'll be waiting for the compressor to catch up from time to time. For one or two projects that could be OK. If you intend to spray a lot then it gets old in a hurry.

 

[dnschmidt]

The two spray guns linked to Spraygunsdirect above are very good for the money. Spraygunsdirect is an excellent place to buy a spraygun due to the pound having gone to hell following Brexit. The British Pound is in the dumpster so their prices are super cheap right now when your paying for them in American dollars.

 

[Isaac-1]

Well now that the holidays are over I can get back to thinking about this project, and I am starting to think the smart thing to do is go ahead and maybe invest in a 3 gun starter set or possible a 3M accuspray kit with mulitple tips for a couple of hundred dollars. Oh I did find the specs on the air compressor, it is an Iron Horse brand 2 stage 60 gallon rated at 11.2 CFM at 90 psi, claimed HP is 6.5 peak, but we all know about peak HP ratings, other sources claim 3.2 HP for this model.