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How much paint do I buy?

23K views 193 replies 10 participants last post by  Lizer 
#1 ·
Hi another Newbie question,
How much epoxy primer should I buy to cover the car, two coats seems right, will a one gallon kit do it?
Also, how much sanding should I do before I spray? I am planning on doing filler on top of the epoxy primer where it needs it.
Thanks!!
 
#3 ·
I agree...also...what kind of car is it...a Vega will take a lot less Epoxy than a 59 Cadillac. Are you doing a complete restoration?...Door jams, engine compartment, inside of the trunk, dash, floor etc. What kind of equipment are you using...HVLP, siphon feed...what tip and air cap...what kind of compressor are you using?...What kind of overall shape is the car in?...How much experience do you have?...Do you have a brand of epoxy in mind?

These are all question that will help determine how much material you need.

Ray
 
#4 ·
Thanks so much for your inputs!
This is a First Time project for me. I am open to all suggestions! The car will not be completely down to bare metal, just the spots where I am grinding the rust down and off. I read some posts that you should epoxy prime first then do the Filler work. Are you saying that is only if the car is totally down to bare metal?
I was going to scuff the car, grind off the rust, epoxy prime, filler, the epoxy prime over that. Are you suggesting that I do the filler first then cover in epoxy prime?
I appreciate your time and experience.
 
#5 ·
You never what any paint under your body filler. Epoxy primer is ok if it is bare metal with epoxy primer on it only. Best is to grind to metal anywhere you need to do any filling. well out past where you need to fill then feather your old paint, epoxy prime, let dry then scuff and then do your filler work.
 
#6 ·
As far as how much sanding you need to do and where to strip again depends on what you are working on and what you want to achieve. Of course the rusted areas would need to be strip, repaired (with metal) ground down with a grinder (about 36 grit), epoxy primed, filled and primed. How much your going to sand depends on what your substrate is like...if it's old paint, or lacquer, or weathered base coat.numerous existing paint jobs...etc. It should be striped. If your dealing with a solid substrate like a base clear that is still in relatively good condition or if the car has been finished in the past with a quality single stage paint and is in relatively good condition, you could sand the remaining of the body with 180 to 280 grit paper (I would recommend this over just scuffing the car, you get more bit with the epoxy if it is sanded properly)and epoxy prime.

These are still questions that would help you get and us give better advice.

Ray
 
#8 ·
Using an electric palm sander is OK....however...what ever you sand will not end up being straight. If you use a 4 inch palm sander, make sure to keep it as flat on the panel as possible and you will need to hand sand corners creases and edges. This will be alright for initial priming....When you sand for paint I would recommend hand sanding with a finer grit on a block using a guide coat to find your high and low spots.

Hope this helps.

Ray
 
#10 ·
Up until lately I would have recommended PPG's DP line of epoxy....then I tried SPI and I must admit I've been converted. I would recommend the SPI for several reasons. SPI can be sanded whereas PPG's DP line does not have great sanding qualities. SPI has respectable build, so with 2 coats you would be getting a decent amount of mil thickness for blocking and straightening out a car. Plus it's got a great price point...It costs about 1/2 of what PPG's DP line costs. As far as quality of product...all I can say is I've tried to abuse it to failure (I mean I pushed it to the limits so if you follow instructions it will last a long time) and it has stood up extremely well.

As far as wax and grease remover goes, yes, use it...sanding will not take off old wax or grease or Armorall or any thing like that. In fact sanding will only grind whatever contaminant you want to get rid of into your existing substrate and give you potential for your new product going over top to fail.

Hope this helps.

Ray
 
#13 ·
Hi Again,
I removed the horrid vinyl top, it was all dried out and torn in places, I used my grinder to get all of the ancient adhesive off and down to the metal. I don't want a vinyl roof so I am going for just a regular roof. So do the spi epoxy then lay down a metal to metal filler over that? Or skip doing a metal to metal type of filler bc of the spi, and i can just use regular filler on top? Thanks as always
 
#14 ·
First Off....Be absolutely sure that your roof is rust free...very often underneath a vinyl roof there is rust due to the vinyl trapping moisture. I would recommend that you strip the roof to bare metal...be cautious of your C pillar (the area between the roof and the rear quarter panel), this is where the factory joined the roof to the rear quarter and filled it with lead. If your using an abrasive like 80 grit on the DA make sure you cut into the lead seam as little as possible. If your roof is rust free using the SPI epoxy over the roof and then doing your body work is fine. If you have rust, repair the rusted areas, apply your Epoxy and finish your body work.

Hope this helps

Ray
 
#16 ·
Hi Ray,
All of your help is super appreciated. So when I start taping and masking the car off to epoxy prime, do I need to remove all the tape very soon after so it's not awful to remove where it pulls and tears at the new paint? Or can I leave the tape and masked areas, through the whole painting process layer after layer? thanks as always.
 
#17 ·
I remove the tape for exactly the reasons you mentioned...I know masking tape is expensive but, repainting the part of the car where the tape took the paint off when unmasking cost a lot more. I like to remove the tape as soon as the primer has flashed (when possible). This way the primer hasn't had a chance to cure and comes of the masked area easily and leaves what you masked off, masked off.

Ray
 
#18 ·
Thanks Ray, sorry to ask, but what does Flashed mean? And how long is that typically?
I was planning on doing two coats of the epoxyprimer, so should I re-mask between the two coats also? Or will painting the two coats in the same session be sufficient for the one masking job? Thanks as always!
 
#19 ·
Sorry for taking so long to respond but I've been a little busy and haven't even had time to check my Emails. Flash is referring to the product (Primer, Single Stage Paint, and Clear Coat) that has been applied to your vehicle, when a product has flashed it means that sufficient solvents have evaporated so that it almost feels dry to the touch. When you can touch the sprayed surface (and I usually touch the masked area, not the sprayed surface) and it's not wet, it has flashed off and your ready for your next coat. It can feel tacky but not completely set up with primers single stage and clear coats, base coat is flashed when it appears to be dry and won't tape mark if you put a piece of masking tape on it. When base coat has reached this stage, it can be clear coated. Flash times are one of the most important components in a quality paint job. If you don't allow proper flash times, solvents can be trapped resulting in sinking, solvent popping and in base coat clear coat applications result in the delamination of the top coat (clear coat). Typically flash times are 15 to 20 minutes depending on the product, what speed of hardner and or reducer you use, air flow and the ambient air temperature. For example if your spraying and epoxy primer using a medium hardner and medium reducer, the temperature that your spraying at is about 70 degrees and you have fans clearing out the air in your painting environment, your applying the primer at a medium wet rate, flash times would be 15 to 20 minutes. If any one of these variables changes, speed of hardners & reducers, air temperature and air flow, the flash times can be faster or slower. Feel your masked area to make sure that the product is setting up, tacky...not wet.

As I mentioned feel the masked area (I use the back of my hand and gently brush it over the area, if I can brush my hand over the primed area and it doesn't mark the primed area and I've waited the appropriate time it has flashed)...Base Coat needs to be dry before it's considered flashed, one of the biggest mistakes painters make is to not allow enough flash time...I have found that if I feel I've done everything correctly, medium wet coats, reducers, hardners, temperature, air flow and I feel the area and it feels flashed...give it another 5 to 10 minutes for insurance, then you know it's flashed.

Leave your masking paper and tape on the vehicle between coat of the same priming session, no need to re-mask between coats.

If you need or would want a more detailed and technical reason for flash times I'd be happy to give it to you. It's a rather long drawn out process to explain what solvents do after they are applied...but when explained many painters seem to understand the importance more readily.

Ray
 
#22 ·
Hi Ray,
I need to cut off some rot in a couple of places, then fabricate a couple of patches to MIG onto the body. Do I replace the metal then Epoxy prime over it, OR do I epoxy prime in the cut out area, then put the patch on over the freshly epoxy primed area? I guess I was thinking it wouldn't be a bad idea to spray into the cut out void.
thanks as always
 
#23 ·
I prefer to cut out the rusted areas, apply a weld through primer on the patches (booth sides) and the body...weld my patches in, grind my welds smooth and epoxy prime. If your cutting out rust, the void your talking about most times has rust in it as well. I like to clean up that rust (grinding or sandblasting) and prime those areas with epoxy primer...if you don't, the rust will spread back to the patch you put in and start rusting all over again.

I hope I explained that well enough, if not let me know and I'll try and go into more detail.

Ray
 
#26 ·
It's always a good idea to clean the area that you are about to prime as well as possible...The cleaner you get the car, the less dirt you will get in your primer. I usually don't pressure wash a car before I prime it...I blow the whole car down followed by wiping it down with a product called "Spirit Wipe", you can use any product that is designed to remove any contaminants from the surfaces that you are about to prime...many people use Wax and Grease Remover, (I use a lot of either of these products when I'm blocking the car...I wet the panel down with a rag and while it's still wet I check the reflection for any imperfections in the body work). These products will also act as a "dust magnet" so to speak. Once the body of the car has been wiped down and is dry, tack the body. I prefer to use a blower while I'm tacking a car down, it seems to get rid of any dust missed when wiping it down.

NOW...the most important part...prime your car...LOL

Ray
 
#27 ·
Hi Ray,
Thanks for all of the great coaching. I am going to prime it next week, yahoo!
After I epoxy prime it, do i need to sand it before I start putting filler down? Or can I wait to sand after all the filler work is done?
Thanks!
 
#28 ·
When you use SPI Epoxy primer there is no need to sand before putting filler down...Below is a quote from SPI's Web-site

On any restoration it is always best to apply the body filler over the epoxy rather than
bare metal for best adhesion and corrosion protection. If one coat of epoxy is used then
the body filler can be applied in 60 minutes. When applying two coats of epoxy, wait
over night before applying the body filler. The epoxy does not need to be sanded before
applying the body filler.

If your not using SPI, you will need to check your tech sheets.

Hope this helps

Ray
 
#29 ·
When you use SPI Epoxy primer there is no need to sand before putting filler down...Below is a quote from SPI's Web-site

On any restoration it is always best to apply the body filler over the epoxy rather than
bare metal for best adhesion and corrosion protection. If one coat of epoxy is used then
the body filler can be applied in 60 minutes. When applying two coats of epoxy, wait
over night before applying the body filler. The epoxy does not need to be sanded before
applying the body filler.

If your not using SPI, you will need to check your tech sheets.

Hope this helps

Ray
 
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