Getting ready to paint my Suburban roof

sprint_9

Rookie
Well I have my Motobase base and I’m waiting for the SPI clear and reducers to arrive. Wednesday it will be warm enough to start painting the cowl/firewall.
I need to look up the pressure settings and tip sizes for each of the paints.
I’m using SPI epoxy as a sealer. What mix ratio should I use and what gun tip and pressure should I use?
After the sealer I’ll paint the base and the clear. Any tips on procedures? This is my first time doing base/clear.
Thanks Paul

Ideally you would use a 1.4 tip from sealer to base to clear, but a 1.3 will probably work if needed. Pressure varies from person to person or gun to gun so its important to set your gun up, here is a good guide SPI provides, Gun Adjusting Guidelines. So with a 1.3 and the info from the guide your pressures are 24-28. As an example, and with a different gun, I was right around 23 for sealer and base, and then bumped up to around 28 for clear.

I liked reducing my epoxy anywhere from 10 to 30 percent, usually in the 20 to 30 percent range though. If short on time reduce more up to 50 percent.

As far as procedure The Perfect Paint Job is the gold standard. I was usually juggling either working my full time job, or playing the weather so it was hard to follow some of it to the letter. I tried to stay as close as my schedule would allow, but I normally would epoxy seal, 4 or so hours later base, then if at all possible let it sit overnight before clearing. I can remember days of sealing around 8am, base about noon, and clear around 5 or 6pm.
 

Willy's Garage

Promoted Users
The HF Black Widow gun has a 1.3 tip. That should be good for the Motobase base. The TDS for the production clear 2100 says to only use a 1.4 tip and only one coat! How long should I wait for doing the clearcoat over the base?
Ideally you would use a 1.4 tip from sealer to base to clear, but a 1.3 will probably work if needed. Pressure varies from person to person or gun to gun so its important to set your gun up, here is a good guide SPI provides, Gun Adjusting Guidelines. So with a 1.3 and the info from the guide your pressures are 24-28. As an example, and with a different gun, I was right around 23 for sealer and base, and then bumped up to around 28 for clear.

I liked reducing my epoxy anywhere from 10 to 30 percent, usually in the 20 to 30 percent range though. If short on time reduce more up to 50 percent.

As far as procedure The Perfect Paint Job is the gold standard. I was usually juggling either working my full time job, or playing the weather so it was hard to follow some of it to the letter. I tried to stay as close as my schedule would allow, but I normally would epoxy seal, 4 or so hours later base, then if at all possible let it sit overnight before clearing. I can remember days of sealing around 8am, base about noon, and clear around 5 or 6pm.
Thanks. I made a few texts yesterday to tech support and those were both recommended.
 

Willy's Garage

Promoted Users
Things are all set but I’m not sure what to mix with the Motobase base 1:1. I’m mixing with my the SPI reducer? I’m so nervous!
 

59vette

Promoted Users
Things are all set but I’m not sure what to mix with the Motobase base 1:1. I’m mixing with my the SPI reducer? I’m so nervous!
As a basic beginner I painted my vette w/ a 3 stage Motobase mixed 1:1. I did use their reducer, but I'm sure SPI's will work. The pros will correct me if I'm wrong. I used med reducer on the color. I understand being nervous, but after proper planning, etc it will work out. Best of luck!
 

sprint_9

Rookie
The TDS for the production clear 2100 says to only use a 1.4 tip and only one coat!

You will probably want to put at least 2 coats on if this isn't a production type job which I gather it isn't.

Things are all set but I’m not sure what to mix with the Motobase base 1:1. I’m mixing with my the SPI reducer?

Yes 1 part basecoat, 1 part reducer, SPI reducer is good. 1 to 2 ounces clear hardener per 32 ounces of ready to spray base for best results.

I’m so nervous!

If this is your first time using this stuff, it really would be worth your time to practice on something that's not in final prep form. I speak from experience on running blind into something like this with a lack of experience your first time. Take a scrap fender, or an unprepped piece from your truck. Mix up some base and run through mixing and gun setup with it, and then after you have base figured out run through the same motions with your clear. You can learn a lot quick on an unprepped piece before you go all in on a prepped piece.

Here are some pictures of my learning experiences, right on top of the factory paint, all I did is wipe off the dust, just trying to go through the motions. You can see where I learned what not to do in the last picture, I was really glad this wasn't on the money piece.


20171224_173237.jpg20171217_164810.jpg
 
Last edited:

Willy's Garage

Promoted Users
So far things are working well. The top was tough to keep a wet edge because of the size. Not really a good place to start as a beginner. The firewall/cowl came out great but there is some orange peel in the white roof. How do I go about putting on another coat of clear? As per The Perfect Paint Job on page 39 of my SPI catalog I put on 4 coats of clear. There is an edge on the top that didn't get enough coats. Do I need to wet sand first and do I have to wait for a certain amount of time?

Paul
 

Attachments

  • white roof.jpg
    white roof.jpg
    13.1 KB · Views: 40
  • cowl 2.jpg
    cowl 2.jpg
    19.2 KB · Views: 40

Willy's Garage

Promoted Users
All along this edge I didn't get good coverage of both the base and the clear. Tech support recommended blending solvent. I've done a bit of searching on the forum and cant find an application like I'm looking at.

Paul
bad roof.jpeg
bad roof.jpeg
 
Last edited:

sprint_9

Rookie
Ok, so just to be sure, your plan is to put more clear on the roof and currently you have 4 coats on it, is that correct? Also, the spot you have that is not coated, is that included in the roof portion that you plan on adding more clear to? Did you activate your basecoat with a small amount of clear coat hardener?

If the answer is yes to the above then you should be able to sand the roof with 800 grit, and scuff any area that is not sandable with a gray scuff pad. From there thoroughly clean with w&g remover, any left over sanding residue will ruin the job. After its clean you should be able to spot in some basecoat on your light spot. After sufficient time for the basecoat to flash I would normally lightly tack off the area that will be cleared, and then clear with 3-4 coats of clear.

If possible move it into the sun for a day or give it a week in the shop if unable to get it outside before starting anything on it.

When spotting in your base use the same settings you used the first time, make sure to try to avoid flooding it on in that small area.

When your sanding be careful not to burn through the clear, if you burn through, those spots will also have to be spotted in with basecoat.
 

Willy's Garage

Promoted Users
Sprint, I added a picture of where the problem is. All along this edge the entire length of the roof there isn't enough base or clear. This really stinks because it is the visible edge of the roof. The seam at the right is the C pillar. I contacted tech support and said that I needed to respray the base and blend the clear. Barry said to use blending solvent which I just ordered. I'm not sure of which of the three Blending Solvent Options on page 6 of the catalog to use.

Option 1: A small area to burn in less than 6 inches.
Spray your base and with a second gun immediately spray one medium coat of blending solvent over the entire area. Let it flash and re-spray the base until covered using the blending procedure on every coat. Apply clear and immediately spray a medium coat of blending solvent over the area. Let if flash and repeat coats of clear followed with blending solvent as needed.
My area is larger than 6"

Option 2: A large area of clear or single stage blending up a sail panel.
Spray the first coat of clear and immediately spray a medium coat of blending solvent over the edge of the clear. Let it flash and repeat coats of clear each followed with blending solvent as needed.
My area is both base and clear so this doesn't work either.

Option 3: A large area of clear of single stage blending up a sail panel.
Spray all your coats of clear and once finished spray a medium coat of blending solvent over the final edge.
This deals with clear and single stage. I've got clear and base.

When mixing the base I didn't use any hardener. Only mixed the motobase LV with SPI reducer 1:1. The body is on a rotisserie and to make it fit in my garage the wheels are off. I can put it out in the sun but it will be a pain. Not saying it can't be done though.
 

elwood

Promoted Users
From what I've been told , one day in the sun equals about seven days inside as far as drying and curing time goes.
 

crashtech

Combo Man
I might just backtape that edge and spot it in. It's an advanced technique though, so I figure you are just gonna have to re-shoot the roof, spotting in the base and re-clearing the whole deal. Unless you can confine the repair area to inside that edge, blending really isn't an option.
 

Willy's Garage

Promoted Users
Well blending didn't work at all. Wound up sanding off all the clear and base to start over. I've got 3-4 coats of white and 4 coats of clear with some orange peel. I've been reading up on wet sanding. It's been a week since the final coat of clear. The body is on a rotisserie so it can't go out into the sun. From the searching on the forum I've been doing it looks like perhaps I should wet sand then put on a couple more coats of clear. Does this sound right?
 

crashtech

Combo Man
If your goal is to have it look super nice, then two rounds of clear is a good idea. Depending on what's going to be done with the vehicle, I might not, since the roof of that rig is above most people's sight lines (unless it's gonna be slammed). You have to answer for yourself whether you want to spend tons of time on a panel few may ever see more than the edge of.
 
Top