Steps to DIY sanding car back ready for respray....

[drunkenmaster]

If you do go for a full respray (ie. bare metal) then I recommend you sandblast as i did on my car below:

http://www.teamazm.com/forum/viewtopic.php?t=4063

I did a previous car by hand and will never waste that kind of time and effort again.

[KILL HSV]

can i ask why you want to go back to bare metal?

[Boostn247]

i dont really want to go back to bare metal!

i just want the easiest, cleanest way of giving my car a new repsray in vx commodore panther mica black...

[KILL HSV]

good choice then, way more work involved in bare metal resprays

[Cubes]

It sounds good in theory to do the job your self but in reality if you don't spend lots of time preparing and do it properly the result will be a crap looking paint job.

I've done it on my first car... One half of one side of the car I spent my time on and looked like glass. Got frustrated and a very very sore arm resulting in the rest of the car looking o.k looking.

[madmoomoo]

Hey Boostn247,

one thing you might want to do is either go to a decent book shop, or even your local library and look up some books. I went down to my local library and have borrowed an informative book on painting etc. I was quite suprised they even had it there. Bonus!

In regards to one of your questions, you asked about driving around with the primer on the car (after the bog filler). From this book I've got, it says that primers generally aren't water proof, and if you go driving around, it's bound to cause problems later on. However, they say that there are two-part epoxy primers that should be used if you're working on the car outside or are going to wait a while before getting it painted.

Hopefully this may be of some use to you.

Good luck with the prep work. Let us know how it all goes, I'd be keen to hear your experiences.

Cheers.

[46n2]

Great stuff on the prepwork info

When it comes to painting and finishing, how do you get the paintwork to gloss-up.

I've done some smaller touch-up jobs and cut the paint back one dried, and it does not come up as glossy as the rest ofthe panel.

Prepwork: I sanded the panel back so surface was even with rest of bodywork/paintwork with ~120-160grit paper. Prepwash and wiped off with a clean rag.

Painted with a spraycan custom mixed to match my paint code. Applied 3-4 light coats, left to dry for ~15 mins between each coat.

Cut back with cutting compound once completely dry (next day), and removed overspray. I was hoping that this would give it a gloss finish, but alas, not the case.

What's the correct procedure?

[silviaz]

Hey all, I'm working on a project car and I believe I made some mistakes. I'm looking to remove the clear coat from my car on most panels (except for panels where the paint has blistered, I will sand this), but wanted to know if these steps are correct?

 

1) Get a red scuff pad (abrasive one) instead of sand paper to remove the shine from the surface

2) get 400 grit sand paper and go over the entire car with a random orbital sander so the surface is smooth and the primer can grab onto something

3) On the blistered paint, go over it with around 120 grit sand paper, go to 240 to smooth out the scratches, then finish on 400 grit.

Anything to add in here or any feedback?

[Murray_Calavera]

8 hours ago, silviaz said:

I'm looking to remove the clear coat from my car on most panels

8 hours ago, silviaz said:

400 grit sand paper and go over the entire car

8 hours ago, silviaz said:

the primer can grab onto something

I'm confused. You said you want to "remove the clear coat from most panels" but it sounds like you are actually doing a full respray?

Few random things to add - 

If you chase the blistered paint with 120 grit, I can almost guarantee you'll chase it down to bare metal (that's fine). But if you paint the car from here, you'll have nice little indents where ever the blistered paint was. The new paint won't magically level out the low areas, you need to fill them.

Which leads me to the main point I wanted to add, make sure the whole car is flat before you paint it. All those areas with blistered paint you sanded out, make sure to fill them and triple check they are flat with a block guide coat. I'd also check the whole car is flat with a large block and guide coat but yeah up to you if you want to go that far. 

 

[silviaz]

On 12/22/2024 at 8:28 AM, Murray_Calavera said:

I'm confused. You said you want to "remove the clear coat from most panels" but it sounds like you are actually doing a full respray?

Few random things to add - 

If you chase the blistered paint with 120 grit, I can almost guarantee you'll chase it down to bare metal (that's fine). But if you paint the car from here, you'll have nice little indents where ever the blistered paint was. The new paint won't magically level out the low areas, you need to fill them.

Which leads me to the main point I wanted to add, make sure the whole car is flat before you paint it. All those areas with blistered paint you sanded out, make sure to fill them and triple check they are flat with a block guide coat. I'd also check the whole car is flat with a large block and guide coat but yeah up to you if you want to go that far. 

 

Yes so in order to paint a panel I need to dull out the existing clear coat as part of panel prep, from what I understand.

 

Ok I'll go higher on the grit mayne 240-300? Then finish on 400 before I do the primer?

 

when you say make sure the car is flat, I was unable to find a block guide coat online. Are you referring to those tubs (image attached) and you use that to see where the imperfections are?

Edited December 23, 2024 by silviaz

[Murray_Calavera]

2 hours ago, silviaz said:

Yes so in order to paint a panel I need to dull out the existing clear coat as part of panel prep, from what I understand.

Maybe more accurately, you aren't just dulling the existing paint, you are giving the new paint something to 'grab on to'. By sanding the existing paint, you're creating a bunch of pores for the new paint to hook on to. 

You can lay new paint over existing paint without sanding it, might last a year or two then sad times. The paint will peal/flake off in huge chunks. By sanding it, the new paint is able to hang onto it and won't flake off. 

2 hours ago, silviaz said:

Ok I'll go higher on the grit mayne 240-300? Then finish on 400 before I do the primer?

Depends on the primer you are using. When you buy your paint, as the paint supplier what grit of sand paper to use before you lay down the primer. 

2 hours ago, silviaz said:

when you say make sure the car is flat, I was unable to find a block guide coat online. Are you referring to those tubs (image attached) and you use that to see where the imperfections are?

Use whatever you like as a guide coat. Pick a colour that really stands out in contrast to the paint. So say your sanding/painting a currently white car, using a black guide coat would work well. You very lightly lay the black guide coat down, then as you sand the car with the large block, all the high spots and low spots will stand out as the black paint is sanded off (or isn't sanded off). 

When you buy your paint, hit up your supplier for recommendations for what paint to use for a guide coat if you're unsure what would work well with your setup. 

[Murray_Calavera]

2 hours ago, silviaz said:

I was unable to find a block guide coat online.

Sorry I should have been more clear with the previous post. 

The block is a sanding block - picture something like this https://motorguard.com/product/motor-guard-bgr161-bgr16-1-rigid-psa-sanding-block-2-5-8-x-16/

The guide coat is the paint

It's two separate things I was talking about, there is no "block guide coat". 

[silviaz]

2 hours ago, Murray_Calavera said:

Maybe more accurately, you aren't just dulling the existing paint, you are giving the new paint something to 'grab on to'. By sanding the existing paint, you're creating a bunch of pores for the new paint to hook on to. 

You can lay new paint over existing paint without sanding it, might last a year or two then sad times. The paint will peal/flake off in huge chunks. By sanding it, the new paint is able to hang onto it and won't flake off. 

Depends on the primer you are using. When you buy your paint, as the paint supplier what grit of sand paper to use before you lay down the primer. 

Use whatever you like as a guide coat. Pick a colour that really stands out in contrast to the paint. So say your sanding/painting a currently white car, using a black guide coat would work well. You very lightly lay the black guide coat down, then as you sand the car with the large block, all the high spots and low spots will stand out as the black paint is sanded off (or isn't sanded off). 

When you buy your paint, hit up your supplier for recommendations for what paint to use for a guide coat if you're unsure what would work well with your setup. 

Ok will do, thanks heaps for the tips there. I'm currently using one of those scuff pads for the entire body where I am removing the shine/ensuring the paint/prime can grip onto something.

[silviaz]

2 hours ago, Murray_Calavera said:

Sorry I should have been more clear with the previous post. 

The block is a sanding block - picture something like this https://motorguard.com/product/motor-guard-bgr161-bgr16-1-rigid-psa-sanding-block-2-5-8-x-16/

The guide coat is the paint

It's two separate things I was talking about, there is no "block guide coat". 

Ah ok, I see. Thanks!

[silviaz]

@Murray_Calavera I was using the scuff pad today and noticed, it didn't take the shine off as easy as I would have thought (Unless I go in a circular motion lol) and will take ages to do the whole car by hand. Would a random orbital sander with a scuff pad attached be the best way to approach it?

One thing I wanted to check when you said to check the areas that I sanded, does that mean if I sanded one area a bit too much (not to bare metal but more than another part of the panel) to make it even I need to put body filler even if there is no damage there?

Edited December 25, 2024 by silviaz

[Murray_Calavera]

2 hours ago, silviaz said:

 I was using the scuff pad today and noticed, it didn't take the shine off as easy as I would

I admire your efforts with the scuff pad. 

As a mere mortal, I use this for the baulk of my sanding work- https://sydneytools.com.au/product/milwaukee-m18bos125-0-18v-li-ion-cordless-125mm-5-random-orbital-sander-skin-only

2 hours ago, silviaz said:

One thing I wanted to check when you said to check the areas that I sanded, does that mean if I sanded one area a bit too much (not to bare metal but more than another part of the panel) to make it even I need to put body filler even if there is no damage there?

Yes you can easily create a low spot while sanding. There are 2 types of filler, 1 part of 2 part. The 2 part filler will get used for large corrections and the 1 part filler will get used for pin holes and areas that only need slight filling. 

Depending on how zealous you are with the sander (very easy to do with a power tool) or if you are chasing rust etc, yes those low spots will need to get filled or you will end up with a very obvious defects in the paint. 

Using the guide coat and large sanding block, high and low areas will be revealed (watch youtube videos for a good visual on this). Its up to you if you think its worth the effort to make the car completely flat before you spray it (you make it flat by filling the low areas). 

At the end of the day, it comes down to time. The end result comes from the level of prep put in to the car. If you want a perfect result, you have to put in the time during the prep stage or else it will be impossible to achieve a perfect result during the spraying process. 

[silviaz]

1 hour ago, Murray_Calavera said:

I admire your efforts with the scuff pad. 

As a mere mortal, I use this for the baulk of my sanding work- https://sydneytools.com.au/product/milwaukee-m18bos125-0-18v-li-ion-cordless-125mm-5-random-orbital-sander-skin-only

Yes you can easily create a low spot while sanding. There are 2 types of filler, 1 part of 2 part. The 2 part filler will get used for large corrections and the 1 part filler will get used for pin holes and areas that only need slight filling. 

Depending on how zealous you are with the sander (very easy to do with a power tool) or if you are chasing rust etc, yes those low spots will need to get filled or you will end up with a very obvious defects in the paint. 

Using the guide coat and large sanding block, high and low areas will be revealed (watch youtube videos for a good visual on this). Its up to you if you think its worth the effort to make the car completely flat before you spray it (you make it flat by filling the low areas). 

At the end of the day, it comes down to time. The end result comes from the level of prep put in to the car. If you want a perfect result, you have to put in the time during the prep stage or else it will be impossible to achieve a perfect result during the spraying process. 

I initially was going to do the whole car with a block then realised, it would be a bigger monster of the job 😂 I guess that's all part of the learning process.

I appreciate all that advice, I think I got a good idea on how to tackle this whole job.

[Murray_Calavera]

8 minutes ago, silviaz said:

I initially was going to do the whole car with a block then realised, it would be a bigger monster of the job 😂 I guess that's all part of the learning process.

I appreciate all that advice, I think I got a good idea on how to tackle this whole job.

You 100% could do that, would save money on a gym membership lol. But yeah, getting a cordless orbital sander will feel priceless coming from doing it manually. 

Good luck with it mate

[silviaz]

Hey guys so turns out this project is going to be much bigger than I thought haha but I've done some my homework and have done a few panels on my car, but one part I can just not visualise is this.

If I do a spot repair and I put filler in a dent for example and sand outside of the repair with 320 grit lets say so the primer can stick as I will only put primer on that repair and the surrounding area and then repaint the whole panel.

Don't I need to make sure that I don't put primer on the old clear coat? I keep seeing YouTube videos where people have new paint and primer land on the old clearcoat that isn't even dulled down, it's still shiny. I thought putting paint on clearcoat or primer on clearcoat is a bad idea because it won't stick.

So in this scenario it's a bit different to mine but imagine someone doing a spot repair and only painting that small section of repair but the new paint is landing on the old clearcoat.

What am I missing?

[silviaz]

Bit of a similar question, apprently with epoxy primer you can just sand the panel to 240 grit then apply it and put body filler on top. So does that basically mean you almost never have to go to bare metal for simple dents?