Hot Rod Forum banner

First Spray gun?

22K views 227 replies 15 participants last post by  carolinacustoms 
#1 ·
Hi

I am completely new to the idea of spray painting. I was looking to paint a few panels on my car. To be specific the fenders and the bumper.

I have been reading a lot about compressors and spray guns but I am having a difficult time making a final decision. I was wondering if someone could help.

My two disadvantages are compressor size and budget. I have a 11 gallon compressor rated at 5.5 cfm @ 40 psi and 4.6 cfm @ 90 psi.

I was wondering if someone could suggest a small spray gun for the job that would work with the compressor. I plan on doing one panel at a time so I am not too worried about compressor size being big enough to do all panels in one.

Also I am not looking to get something too high quality, something mid range. Thanks in advance.
 
#2 ·
First of all, welcome to the site...and you probably made a wise choice in asking before you purchased. Unfortunately virtually every gun will require more CFM than your compressor puts out....and that's if the compressor manufacturer isn't lying to you about CFM output (most compressor manufacturer's embellish the CFM output). You could purchase a small Harbor Freight touch up gun...they are inexpensive, don't hold much paint and if your going to be spraying one panel at a time, letting your compressor cool down between panels, you might get away with it.

Before you purchase a touch up gun, check to see if the CFM requirements can be handled by your compressor...if it requires 6 or 7 CFM, the compressor will run continuously and you will have a drop in air pressure at the gun. If your spraying a solid color, it's not that big a deal...if your color is a metallic, the color will change as the pressure drops.

I hope this helps, if you need more information, let me know, I'll try and explain further.

Ray
 
#3 ·
Thank you for your reply.

I did realize that my compressor is very small in size. That is one of the biggest issues. I can shell out some money on a compressor or a good gun, but not both.

I intend on painting panel at a time as I said. And I am not painting any metallic colors. Just solid silver.

I was reading that the best choices are mostly gravity fed HVLP guns but as you said the compressor is too small for most guns. In that case should I go for a LVLP gun to fit my compressor range? Or just try a relatively cheap gun from harbor freight or home depot that falls somewhere close to the rating?
 
#5 ·
A lot depends on how fussy you are...a compressor big enough to handle a full size paint gun will usually cost more than a quality gun...If budget is a concern, perhaps even try a small siphon feed touch up gun from Harbor freight...they are cheap (under $30.00..I think) and you may just get lucky and be able to complete a panel.

I'm sorry, I don't know what a solid silver is...silver's in the automotive paint world are mostly metallic's...are you using automotive paint? If so, what kind...brand...ie Acrylic Enamel, base clear?

Ray
 
#6 ·
So I went to home depot after work just to look at some compressors. And as you said they were really expensive compare to the spray guns I looked at online.

I looked at some spray guns also and I found a Husky HVLP gravity feed which was rated at 4 cfm @ 40 psi. It had a recommendation of using a 8 gallon compressor on the box. What do you think about that gun with my compressor?

As to the paint, haha sorry you are completely correct. There is no such thing as solid silver. After looking at my color code the color I would need is a sleek silver metallic.

Honestly I don't really know much when it comes to paints and clear and top coats and such; so any advice would be much appreciated. I know that I am imposing too many limitations but my expectations for the end result are not very high. I would be more than happy with the result being just okay to decent.
 
#7 ·
If you found a paint gun that uses 4 CFM, your expectations are that it may turn out less than 100% and it falls into your price range...then you very well may have a starter set up that will get you through some paint work.

Chances are that your car was painted in base clear, if you need advice moving forward, let me know and I'll try and walk you through the steps and materials needed to paint your panels. Remember, automotive paint isn't cheap...your material bill will be much more than your paint gun.

Ray
 
#8 ·
Great! I will go ahead with the gun then.

Your help would be great. I can tell you what I know/understand so far and if you can lead me from there or clear any misunderstanding I have I would greatly appreciate it.

The panels I got are primed. According to what I have read I should rub it with some lacquer and if the priming rubs off that means it is not an e-coat priming. If it is I can go ahead wash and de-grease and then start with sanding (I can't exactly remember what grit) and scuffing. After I am done with the following I can start with the painting. I still have to do more research as to what paint, how many layers and such. Also I was reading that getting a moisture absorber for the compressor is necessary.

So if you can guide me further that would be great.
 
#9 ·
Okay, first of all, I'm not going to give you information overload... we can go through the processes step by step. True, if the coating on the panels washed of with thinner, it's not an E coat and should be removed and replaced with an Epoxy primer. In a perfect world, even if it is an E coat, an Epoxy primer is still a good idea. It acts as a buffer between the the substrate and the top coat.

Before anything is sanded, we need to find out what type of paint your going to apply...it will be either single stage or base clear...for base clear (you could use these grits for single stage as well but single stage can be sanded with coarse paper like 320 grit), the panels can be sanded with either 400 grit dry paper or 600 wet (I can explain the difference if you like). This will leave you a footprint fine enough so that sand scratches won't show up.

So lets find out what kind of coating you have, (I still feel more comfortable with an Epoxy cushion but, your call) and what type of paint your going to be using and we can take it from their.

Ray
 
#10 ·
Okay step by step sounds even better.

How do I know whether I need to go with single stage or base clear? Is that something specific to a car or depends on the users choice?

And if you can explain the difference between the wet and dry sanding that would be good. That way at least I know the reasoning behind it instead of blindly doing something.

If the adding the epoxy primer is something that does not incur a huge extra cost then I would have no issue with doing that step as well.

In case it helps, I have an 07 Hyundai Sonata. My color code is K1. Silve sleek metallic.
 
#11 ·
Let's start at the beginning, an 07 Sonata will be base clear paint from the factory. Don't try and paint it in single stage, being that it's a silver, single stage will look dull and drab beside base clear (let alone that there aren't any variants in color formulation in single stage).

The difference between wet and dry paper is what it sounds like. Dry sand paper can only be used dry, wet sand paper can be used wet or dry and is more aggressive than dry paper...that's why the difference in grits used...400 dry versus the more aggressive 600 wet. 600 wet is a bit messier but does a nicer job, last longer because the water acts as a lubricant and cleans the paper while sanding and the sanding sludge cleans off the panels easily.

One thing to remember when sanding, if your not using a block (a block is a piece of equipment used to ensure that a panel stays straight or gets straighter when sanding primer) is to use the palm of your hand and not your fingers, If you use your fingers, chances are lines in the form of your fingers will show up in your paint (yes, it's that fussy).

If your going to do the thinner test on your panel, check the inside of the panel, not the outside. It's not a good idea to get lacquer thinner on anything that you will eventually be painting.

Ray
 
#44 ·
Let's start at the beginning, an 07 Sonata will be base clear paint from the factory. Don't try and paint it in single stage, being that it's a silver, single stage will look dull and drab beside base clear (let alone that there aren't any variants in color formulation in single stage).
And single stage silver is not for the novice painter. You will get streaks and blotches, as you must wet it enough to shine, while avoiding the streaks and blotches.

The difference between wet and dry paper is what it sounds like. Dry sand paper can only be used dry, wet sand paper can be used wet or dry and is more aggressive than dry paper...that's why the difference in grits used...400 dry versus the more aggressive 600 wet. 600 wet is a bit messier but does a nicer job, last longer because the water acts as a lubricant and cleans the paper while sanding and the sanding sludge cleans off the panels easily.
For a high metallic light color, (silver) I prefer 600 dry and 800 wet.

One thing to remember when sanding, if your not using a block (a block is a piece of equipment used to ensure that a panel stays straight or gets straighter when sanding primer) is to use the palm of your hand and not your fingers, If you use your fingers, chances are lines in the form of your fingers will show up in your paint (yes, it's that fussy).
Especially in light metallic colors. and will still be there after the clear has been sanded flat.

If your going to do the thinner test on your panel, check the inside of the panel, not the outside. It's not a good idea to get lacquer thinner on anything that you will eventually be painting.

Ray
I've heard that and allways wondered why.
 
#13 ·
Okay I follow so far.

It has to be base clear for reasons you mentioned.

If 600 wet is better I would do that as man hours is something I have plenty of. I can buy a sanding block but if I do not I will make sure to use my palm.

I will also take care to test the inside of the panel with the lacquer thinner.

Assuming it is an e-coat I would proceed straight with 600 wet sanding? Do I need to give the panel a good wash before the sanding or the wet sanding takes care of that as well.
And if it is not an e-coat do I still go ahead with the same grit or is the process a little different.
 
#14 ·
If the coating on the replacement panels is an E coat...it can be top coated after it has been sanded. One thing I should mention as well, one panel you mentioned was a fender I believe...that fender will have areas that sand paper cannot get into, for those areas a "Gray Scotch Brite" pad can be used to rough up the E coat.

I do custom work and don't see to many vehicles as new as yours...Virtually everything I do is brought down to bare metal and the substrate built up starting with Epoxy Primers...that being said, in body shops, it is common to paint over top of of an E coated panel.

You asked a very good question in should you clean the panel before you start sanding. the answer is Yes, the reason is that if you don't and there is contamination on your E coat and you start sanding the panel, the contamination could get ground into the E coat and cause problems down the road. the panel should be cleaned with wax and grease remover. This product is applied by using a lint free towel with wax and grease remove on it, and immediately followed by wiping it off, removing all the wax and grease remover...this will clean any contamination that has accumulated on your new panel from shipping or the guy that had a cheese burger for lunch, didn't was his hands and wrapped your panel. Wax and grease remover can be purchased at any automotive paint supply store...if you want to save a little more money compared to their prices, there are options.

If the coating that's on your panels is not an E Coat, my best advice would be to remove it...because we don't know what it is and if it comes off with thinner, that means that chances are that it will absorb moisture...and moisture is not your friend...also if thinner takes the coating off, it would be considered an unstable substrate. You could take your chances and sand it as though it was an E coated panel and then paint it...it all depends on how much you like your car and how long you want it to last.

If you do decide to strip the panel and re coat it...this is where a Quality Epoxy primer comes in...if this would be your plan of attack, let me know and I can recommend a primer that is user and cost friendly and works well...also shipping would be free...No, I don't work for that paint company...LOL

I hope this answers your questions, let me know how things go and we can move forward.

Ray
 
#15 ·
Okay that clears up a lot.

My panels should be arriving within this week. Or early next week. Should I do the steps that you have explained so far and then just reply to this thread on how to proceed further? Or would you prefer to dish out all the instructions now regardless of when I receive the panels?

Either case is completely fine with me as you are using you free time to help me out. I have posted on many forums and have received absolutely no answer so this is unbelievable helpful to a novice like myself.
 
#18 ·
At $60.00 you must have had material on hand, know somebody in the trade that cut you a deal...or you stole the product and paid $60.00 for the gun...Just joking (about the steeling part...the rest, well, you got a deal somewhere). The prices you paid in all probability won't reflect what OP will be paying. A pint of Silver will eat the $60.00 fairly quickly...let alone the clear coat....Right?

Ray
 
#19 ·
Before I receive the panels and proceed with what you told me one thing I wanted to clarify. Before the sanding in the cleaning process, I just wanted some clarification. Do I need to apply wax and grease remover or one of the two would suffice?
Also it it okay to leave the panels after they have been sanded or the painting process needs to start immediately?
 
#20 ·
I'm so sorry, I should have explained myself better...Wax and Grease remover is a product...one product, that is called "Wax and Grease" remover. It's a very common product in the trade and I wasn't thinking that you might feel that it was 2 products.

The panels can be stored after they have been sanded...If I store a piece that is prepped for paint for any period of time, I'd go over the panel before painting with that "Gray Scotch Brite" pad that I mentioned earlier, just to remove any thing that may have landed on the panel...also, just before painting, the panel needs to be cleaned with Wax and Grease remover again...Keeping surfaces clean is of utmost importance, a clean panel directly reflects the quality of the finish.

Again, I apologize and can see why you would wonder which product to use...I will remember this for future reference.

Ray
 
#21 ·
Oh haha! no that is no problem. It is only because this is my first time doing anything related to painting panels.

Once again I appreciate the explanation and clarifications. Once I receive the panels I will go ahead and do the steps mentioned up till now. Then I will reply for further instructions. I'll post some pics also just for the heck of it.
 
#24 ·




So I received my first panel today.

I also went out and bought the following (also shown in the image)
1. 600 wet sanding paper
2. Scotch brite pads
3. Sanding block
4. Auto cloths (microfier)
5. Lacquer thiner
6. Wax and grease remover

I put some lacquer thinner on a cloth and paper towels and rubbed it on the inside and it seemed to rub off. Picture shows this.
So that means it is not an e-coat?
If from this point I want to strip the metal and re coat it, how do I go about doing this?

Also I am not sure if you can see images. If not they should be uploaded on my profile also. It only gives me the options of inserting links. So let me know if it doesn't work and I can upload through dropbox or something. Thanks
 
#25 ·
I'm sorry to hear that it wasn't an E-Coated part...I assume that you don't have a DA (Duel Action Sander)...if you don't, you could either sand it off by hand using 80 grit sand paper or, get a chemical stripper...or do the forbidden, wash it off using lacquer thinner...my first question would be, how fast did the thinner take off the coating? The reason I ask is that if the thinner takes it off but, takes it off slowly, sanding the panel or stripping the panel with a chemical stripper may be faster...if the thinner does take off the coating quick enough and that is the method you choose, wear gloves and even a respirator, the fumes can make you nauseous. If the thinner method is your method of choice, after the material has been removed the raw metal must be cleaned with Wax and Grease remover several times to ensure that any residue from the thinner is removed...then the metal must be sanded with 80 grit paper to rough it up for the proper Epoxy Primer. If you would like to purchase a DA, they can be purchased quite cheaply at Harbor Freight...probably around the $30.00 mark...complete with a backing pad for 6 inch sand paper. If this is the route you take, let me know and I will inform you on how to properly strip a panel using 80 grit on the DA. Chemical stripper is toxic, messy and usually would cost as much or more than purchasing a DA...if this was my panel, I would consider getting the sander...then when your done, you have another tool that may come in handy in the future.

There may be some that will tell you that they have top coated the existing type of coating that you have and never had a problem...my answer to that is in my 30 plus years of doing this, I have seen many problems when a substrate such as what you have on the panel is not removed and a base coat/clear coat paint is applied.

After you have the panel stripped, you will need some Epoxy Primer. The best product when it comes to Epoxy Primer that I have used is SPI's Epoxy Primer. The product is available in Gray (which will help when painting the panel silver), the part number is 6610-4 for the primer, the activator is 6700-4. The cost is $33.75 each for the primer and activator and shipping is free. This product provides excellent adhesion, great rust protection, can be top coated within 7 days after applying without sanding...but...can be sanded as well, which, for an Epoxy Primer is a bonus. It does sand very well for an Epoxy. This product will give you the cushion between the metal and the paint that I mentioned earlier.

There website is

Home

If you decide to get this product, again, let me know and I will walk you through the proper way to mix it and apply it. Also, before and if you intend to order this product, again, let me know. There may be other products that they have that you may need and could be ordered at the same time.

Hope this helps and sorry that the panel wasn't an E-coated panel. Very often when an individual does the type of repair that your doing, they begin to understand why a body shop charges as much as they do...LOL

Ray
 
#27 · (Edited)
Haha I will def have a deeper appreciation for body shops after all this.

The thinner seems to take it off decently fast but I think I will take the route of the DA. That way I can have it for use later on and I will not be committing the forbidden lol. Would the sander however be compatible with the compressor. I checked online and the sander is rated for 4 cfm @ 90 psi and the compressor is 4.6 cfm @ 90 psi. Seems to be in the range to me ....

As for primers I think I will go with your suggestion since my knowledge about primers is close to 0. I do want to ask that with one purchase of each, the primer and the activator, how long do they last. As in, are they enough for a small panel or they can cover more?

I can run by harbor freight to pick up the sander tomorrow.

I can't see them in the post but if I right click on them and click the option saying open in a new tab/window I can see them.
Try this link. It should open a site and you can download the folder that says body work.
https://www.dropbox.com/sh/4tivtsfzth3ekez/PGbuwqiVAQ
 
#28 ·
The DA route is the the prudent choice...as mentioned, you will have something to show for your money after your panels are painted. Seeing that your compressor has a low CFM rating what you will need to do is not run the sander at maximum air pressure. The sander should have a valve to control air pressure,if not, the trigger could be used as a throttle for your sander and you can control the speed making your compressor compatible to the sander...it will just take longer.

With respect to how long the primer would last...they can do more than one panel...you will have 2 sprayable quarts of Epoxy primer...when your other panel/panels come in (what are you all planning on painting?) depending on size, we will mix what we need, seal the cans and only apply what is mixed...I'm sure you will have primer left over. The self life of the product is...well they have a factory recommended self life...it's longer than what they recommend, the manufacturer is being on the safe side. I've base coat that was properly sealed and 10 years later it sprayed well.

Before you order the primer, we should consider what you are going to use for clear coat. I always purchase mine by the gallon...you don't need a gallon and I'm not sure if they make sell their clear in quarts...I'll call for you in the AM and find out...if the SPI clear is the clear you want to use, again, I've used many clears, SPI's product is as good or better than any out there and priced much better.

I will check to see if I can load your pictures...so far, no luck.

Ray
 
#30 ·
Okay so I put some thinner on paper towels again.

Rubbed it as hard as I can for a good 30-45 seconds. And I think you are right. Click on the link to see the image of the towel. I could not get to bare metal.
https://www.dropbox.com/sh/4tivtsfzth3ekez/PGbuwqiVAQ

If you are right then sorry for making you waste all that explanation :( though at least now I know how to proceed if it was not an e coat. Thanks
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top