Painting primed panel.
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Hey guys,
I have been reading this site on and off. Thank you so much for sharing.
Now I have a few questions for you.
There are little chips on primed hood out of the box.
Do you fill it with a glaze sand then spot prime?
Should I scuff the hood down with gray pad before applying base?
How much paint should I get for project involving two bumpers, tail gate and the hood?
Thanks.
When you get new parts like that, there are usually small defects. Typically the metal panels are sanded with a DA using 400 grit to remove imperfections and help with adhesion. The edges and inside are usually scuffed with a scotch brite pad. Unless there is damage (dented) it won’t need any filling. Plastic parts (like bumpers) get cleaned then usually just scuffed with a grey scotch brite pad (sometimes wet with prep paste). Everyone preps them a little different, but that is pretty typical.
Then the most common thing to do is to blow the parts off, clean the parts (wax and grease remover for the metal parts, and plastic cleaner for the plastic parts), then go over them well with a tack rag.
The next part will vary depending on the products you are using…but typically, the plastic parts will get adhesion promoter on all bare plastic surfaces. The metal parts will get etch primer on all bare metal areas. Following a proper flash time, all the parts would get 1-2 coats of a good 2k wet on wet sealer. Following proper flash time you can proceed to basecoat and clearcoat as usual. I highly recommend using a flex additive in the sealer (for the plastic bumpers) and you should use the sealer that is recommended to go with your base coat. Applying basecoat directly over the new primed panels is not advised.
What brand of paint materials are you working with? Solvent or water base?
Good post Ben. Thats exactly how i would do it.
Thank you for the reply, Ben.
I have done panel painting before with aerosol with good results but nothing to this scale.
I already HVLP gun with a 26 gal compressor that can push CFM for the gun and have all the filters and such to get good air supply.
It seems as if you read my mind, I do have a rear bumper that already has good coat of factory paint that does not match the current color and the front is with the primer from the factory.
Is the sealer same as the primer? What does a sealer do? How long is the flash time usually? I suppose the flash time varies with different paint? Why wouldn’t you basecoat over the new primed panel?
Sorry for the rather elementary questions.
I am looking to use Urethane base coat over Acme Finish 1 clear.
Do you think 2 qt of base would be enough paint to cover the mini’s hood which is about 2/3 size of the normal hood and the two bumpers? once again about 2/3 size of the normal sized bumper.
I have been a shade tree mechanic for 17 years working on Jeeps. This is my first time doing painting the car at this scale. I want to learn as much as possible. I am in the process of creating a booth similar to that of Nexson.
Thanks much and for your patience.
[quote=”DailyDrivenMini” post=26460]Thank you for the reply, Ben.
I have done panel painting before with aerosol with good results but nothing to this scale.
I already HVLP gun with a 26 gal compressor that can push CFM for the gun and have all the filters and such to get good air supply.
It seems as if you read my mind, I do have a rear bumper that already has good coat of factory paint that does not match the current color and the front is with the primer from the factory.
Is the sealer same as the primer? What does a sealer do? How long is the flash time usually? I suppose the flash time varies with different paint? Why wouldn’t you basecoat over the new primed panel?
Sorry for the rather elementary questions.
I am looking to use Urethane base coat over Acme Finish 1 clear.
Do you think 2 qt of base would be enough paint to cover the mini’s hood which is about 2/3 size of the normal hood and the two bumpers? once again about 2/3 size of the normal sized bumper.
I have been a shade tree mechanic for 17 years working on Jeeps. This is my first time doing painting the car at this scale. I want to learn as much as possible. I am in the process of creating a booth similar to that of Nexson.
Thanks much and for your patience.[/quote]
If you haven’t painted with the gun before, I strongly suggest practicing a bit before doing this one.
A 26 gallon compressor may put out the CFM you need, but I suspect it will be working awefully hard. As you know, you will likely get a lot of condensation/water in the air lines, make sure your filters can handle the water!!!
Primer is really a vague term. But yes, sealer is basically the same thing as a sandable primer surfacer…just with sealer you use it wet on wet without the need to sand among other differences. Typically with sealer it needs to flash about 15 minutes before applying your basecoat (and they usually have a window, if you wait too long you will have to sand the sealer). Some of the reasons we use a sealer rather than just apply base coat over the new parts are:
-chip resistance (the sealer acts as a cushion preventing stone chips)
-adhesion, urethane sealers get superior adhesion to the factory e-coat primer
-hiding/coverage, using a sealer the right shade of grey (or colour) will help when spraying your basecoat colour
-corrosion resistance, sealer gives better protection compared to not having it.As for the paint, colour matching can be an issue. Some colours are better than others as well as some brands of paint tend to match better than others…don’t cheap out too much on the product. In addition to that, there may be several variants of the colour you are using. For most colours, most people usually blend the colour into the adjacent panel(s) to prevent colour mismatch issues.
As for the basecoat, the quantity needed will vary depending on the colour, brand/type of paint and your application. But, if you are talking about 2 qts unreduced, I would imagine that should be more than enough. With my product, I would probably use about 1.3qts reduced, ready to spray, depending on the colour.
Great advice so far.
Ben thank you so much for giving me all these guide lines. I really really appreciate it.
In one of the my posts, I meant to say “clear over base” not “base over clear.” Was getting late..
I picked up 1 Qt of Urethane base with a gal of reducer and 1 gal clear coat with activator. Paid $225. He threw in breather, a few mixing cups, strainers, and a breather. It is a mom and pop shop in SC, called Prospray if anyone care to know.
With the base coat, I was told that it can be mixed 1:1.
In terms of blending I was told that I can reduce the base further down with the reducer and spray that.
I was also told not to paint over this primed hood directly from the paint shop owner, he recommended priming again after scuffing it down, just as you said, Ben.
More Questions:
1. What is the repercussion of using aerosol primer? I saw epoxy primer at Lowes in aerosol can and also have seen “sandable” primer.
2. What is the typical flash time between base coats, between base coat and clear, and clear coat and clear coat?
3. If bondo, el cheapo version, is used, how long do I wait before I can prime and paint over it?
4. For cleaning, should I buy cheap lowes mineral spirit or paint thinner? Is either of them ok?
5. For the bumper with good factory paint, do I just scuff it down with gray pad and base coat?
6. Once scuffed, do I clean it with water or cleaning solvent? How long do I wait?
7. Which Ajax cleaner is ok to use? Can I use one with bleach?
Thanks again for wonderful information!
[quote=”DailyDrivenMini” post=26473]Ben thank you so much for giving me all these guide lines. I really really appreciate it.
In one of the my posts, I meant to say “clear over base” not “base over clear.” Was getting late..
I picked up 1 Qt of Urethane base with a gal of reducer and 1 gal clear coat with activator. Paid $225. He threw in breather, a few mixing cups, strainers, and a breather. It is a mom and pop shop in SC, called Prospray if anyone care to know.
With the base coat, I was told that it can be mixed 1:1.
[color=#000088]That is typical for solvent base coat. Make sure to practice spraying first, so you may want a little more base[/color]
In terms of blending I was told that I can reduce the base further down with the reducer and spray that.[color=#000088]A little extra reducer can be used to blend (just don’t reduce it too much). But most of the time it is not necessary[/color]I was also told not to paint over this primed hood directly from the paint shop owner, he recommended priming again after scuffing it down, just as you said, Ben.[color=#000088]As mentioned, primer surfacer and primer sealer are similar. Spraying with the surfacer and scuffing is fine, but on new parts is only a wast of time compared to sealing instead[/color]
More Questions:
1. What is the repercussion of using aerosol primer? I saw epoxy primer at Lowes in aerosol can and also have seen “sandable” primer.
[color=#000088]Lowes=house not car :p Most automotive primers are a catalyzed urethane (aerosol products are not catalyzed). Automotive products are much more durable, possibly more flexible, may have much better adhesion and corrosion resistance and are compatible with your basecoat.[/color]2. What is the typical flash time between base coats, between base coat and clear, and clear coat and clear coat?[color=#000088]You really need to get the tech sheet for the product you are using and go over that. The place that sold you your paint should supply you with a copy. But typically between coats of base is about 5 minutes, 15 minutes before clear coat and about 5 minutes between coats of clear[/color]
3. If bondo, el cheapo version, is used, how long do I wait before I can prime and paint over it?
[color=#000088]Most fillers can be primed over with a 2k urethane primer surfacer as soon as they are sanded[/color]4. For cleaning, should I buy cheap lowes mineral spirit or paint thinner? Is either of them ok?
[color=#000088]I highly recommend using automotive wax and grease remover or final wipe solvent. Occasionally you can buy these in 1qt cans. It is usually relatively inexpensive, even the good name brand stuff.[/color]5. For the bumper with good factory paint, do I just scuff it down with gray pad and base coat?
[color=#000088]Yes, if you scuff it well enough, definitely. IF you break through layers of paint you may want to apply some primer or sealer[/color]6. Once scuffed, do I clean it with water or cleaning solvent? How long do I wait?
[color=#000088]Before starting, wash it with soap and water so you start with a clean part. When done, a good cleaner for plastic, especially if you are on a budget is isopropyl alcohol[/color]7. Which Ajax cleaner is ok to use? Can I use one with bleach?
[color=#000088]Don’t bother. The alcohol will work well.[/color]Thanks again for wonderful information![/quote]
Ben, how much would you mix to spray a bumper? Hood? Separately.
I just want to conserve or mix just about right amount so I don’t mix short of or more than I need.
Thank you so much for your help!
Michael
[quote=”DailyDrivenMini” post=26487]Ben, how much would you mix to spray a bumper? Hood? Separately.
I just want to conserve or mix just about right amount so I don’t mix short of or more than I need.
Thank you so much for your help!
Michael[/quote]
Again, there are many variables…but for 1 bumper on a mini, I would probably mix 12 ounces of colour, ready to spray, and for the hood about 20 ounces ready to spray. As for the clear, it varies quite a bit, some high solids clears seem to go a long way compared to medium solids clear. Maybe 10oz for bumper and 15 oz for hood? But those are pretty rough numbers. Mix on the low end if you are concerned…you can always mix a little more as needed.
Started painting. Have some runs. Do I fix them after it is dry?
I also have a bug stuck under the paint. Sand it down once it sets and repaint?
I suppose I fix the defect first and them clear on top?
Thanks again.
MK
Is this in the basecoat or clear coat?
If it is in the base, you can let the base dry for a while (probably at least 1/2 hour) and gently wet sand out with 800-1000 grit, you will need to rebase after. If the runs are bad, you may not be able to fix them easily this way.
If you ran the clear, minor issues can be sanded out and polished after it is dry (next day). If there are major issues you are better off to let it dry a day or two and start over.
Post some pics if you can
I fixed the base.
I was doing the 50% overlap with clear and I do have some runs.
I will post once everything is fixed up. This is embarrassing. :rofl
Don’t worry about it. There is a steep learning curve to painting. No one gets perfect results the first time…it takes years to get good, and even professionals get runs now and then
How long should I wait before wet sanding the clear? I had the medium activator.
Which grit?
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