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Primer question

3K views 7 replies 5 participants last post by  69 widetrack 
#1 ·
I have a truck and I am in the process of wed sanding the entire truck with 320 and some 280 in a few spots.

There are a few places where I have used filler.

The paint will be just an enamel for this daily driver but my question is I first want to spray the entire truck with a good primer.

My question which primer to use under enamel paint?

Thanks Jimbo
 
#2 ·
Use a quality Epoxy primer. I prefer SPI Epoxy, it offers great rust protection, makes an ideal substrate for virtually all automotive refinish products, has good sanding qualities, filler can be applied over top of this primer, it comes in White, Gray, Black and Red and is priced properly compared to other automotive Epoxy Primers.

Here is the website and shipping is free.

www.southernpolyuretyhanes.com

The customer service is great as well.

Hope this helps.
 
#3 ·
What color primer?

I thing I forgot to mention is that I will be painting the truck a dark red color.

Should I use a darker primer under a red?

The paint on the truck now is a base/clear coat that is a deep metallic red color that was done about six or seven years ago and the clear coat on the roof and flat areas is coming apart.

Jimbo
 
#4 · (Edited)
Red is notorious for poor coverage, I generally use the
SPI red epoxy first, it really helps.
I would use a red that is a little lighter to help the color.
I just finished a topper that was going to be a real bright red
The color chip for the final color was just a shade darker than the truck,
so I mixed a little red with some white epoxy and painted it pink first.
It helped to lighten it ever so slightly.
It matched perfectly.
For a dark red I would have used the red epoxy full strength.
 

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#5 ·
I understand what your saying and I also understand what jcclark is saying...Dark Red...is only part of the information needed to determine what shade of primer will give you best coverage. It's more the shade of the primer than the color that will give you optimum coverage. I will now need to go back to my Dupont days and explain the value of color.

All colors have a value or degree of darkness and lightness, this value, when used in the form of a primer will greatly assist you in getting the most coverage out of your top coat. What you could do is take a sample of your color (a color chip from your paint manufacturer would work) photocopy it with a black and white photocopier....the shade of the color will come out between White and Black in a form of a gray...the darker the color, the closer to Black, the lighter the color, the closer to White. Whatever shade of Gray the photocopier gives you (a photocopier that has a good balance between White and Black would be great) will tell you what value and what shade of primer you need.

Depending on the darkness of your Red paint, a Red Epoxy may nor be your best bet...a Black or combination of Black and Gray may serve you better. I hope this explains the value of color, if you need more information, let me know and I'll try and explain further.

With respect to the clear coming off of your truck...good advice would be to remove any and all paint and start over...if that's not going to be part of the plan...at least remove the paint from the top surfaces where the paint is "coming apart". If this where my truck and I really liked it , I would take a look at how much I was investing in paint material and ask myself if I wanted to risk putting that investment in over a substrate that is already "coming apart". Reds are real pricey...so give it some thought.

Ray
 
#7 ·
if you're only going up to 320 why wet sand? You can dry sand 320 just fine(depending on paper) and not have to worry about edges with bare metal poking up. If I wet sand a primer and go thru the efforts it will be a 500-600, where the difference is noticeable from a 320 scratch. Just my thoughts. I'd say 320 is pushing it with a bright red but lots of guys do it. When it's all said and done and cured and if you stare at it long enough you might see a few scratches or your metalics will reflect their outline. Don't get that with 500-600
 
#8 ·
True Henry, using a coarse grit like 320 and having sand scratches show through is quite common in a base coat paint because base coats are that much thinner than Enamels or Acrylic Enamels. The thin metallic base coat will have the metallic's land in the 320 grit sand scratches and they will very often be visible. With Enamels and Acrylic Enamels this is not as common due to the shear thickness of the top coat....for me, I sand anything and everything with a minimum of 600 wet when spraying a solvent based top coat, and yes you need to be aware of sanding through the primer as wet paper cuts faster than dry but, it does leave a smaller sand scratch foot print and eliminates the possibility of sand scratches showing up in your finished product.

Now, with water born base coats, the base is even thinner than solvent and everything needs to be finished in 800 wet.

Ray
 
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