Sanding grit for 2K primer befor Epoxy - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Body - Exterior
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 02-10-2012, 06:11 PM
Registered User
 
Join Date: Feb 2012
Location: North Carolina
Posts: 18
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Sanding grit for 2K primer befor Epoxy

I sprayed the entire car with Nason Select-Prime 421-19 2K urethane primer and block sanded to P400 dry. I then sprayed the two front fenders, the hood and the trunk lid with Nason Ful-Poxy 491-16 Epoxy primer blocked sanded dry to P400 and wet sanded to P500 ( I am planning to spray the whole car with Epoxy but my heated space is limited to panels at this time). I have now been told that urethane primer sanded with P400 is too smooth for proper epoxy adhesion and it may peel when topcoated. Can anyone confirm or deny this? I can find nothing in the Nason 491-16 Epoxy Primer technical Manual about what grit to sand the old finish with. Help!!

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-10-2012, 07:44 PM
Registered User
 
Join Date: Feb 2012
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
sand epoxy primer

I have sanded primer with 360 and 400. I really don't see the need to go all the way down to 500. I have never heard of primer being sanded too smooth that the top coat would peel off. big thing is get the tech sheet on the product you are using. The body supply shop always has them just ask. What will cause problems is not getting the mix right, using more than one product line, or depending on the product not letting it flash off long enough/ or waiting two long between recoat window. i have painted single stage, lacquer, syenthic enml, and old school enml. what will cause adhension problems is a dirty surface or mixing product lines. I hope this was helpful. You should really start off with the supply house where you bought the product you are spraying. light sound stupid put some manufactures put the info right on the can label
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-10-2012, 08:01 PM
Registered User
 
Join Date: Feb 2012
Location: North Carolina
Posts: 18
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I may not have been clear in my first post. What I am being told is that because I sanded the 2K urethane primer to P400 (too smooth) before spraying the Epoxy primer, that the epoxy primer will not stick to the 2K urethane primer properly. The Nason tech. sheet for the epoxy primer says nothing about what to sand the surface with except for bare metal 180 grit.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-10-2012, 11:03 PM
Registered User
 
Last photo:
Join Date: Feb 2011
Location: Kalamazoo, MI
Posts: 1,113
Wiki Edits: 0

Thanks: 62
Thanked 94 Times in 79 Posts
if that's what the nason tech told you, why wouldn't you listen to him?
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-11-2012, 07:19 AM
Registered User
 
Join Date: Feb 2012
Location: North Carolina
Posts: 18
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The Nason Tech. Sheet says "properly sanded finish", it does not say what grit to use. It also says "bare metal must be sanded with 180". Also the person that is telling me that urethane primer sanded with P400 and then sprayed with epoxy primer does not know for sure and has never sprayed epoxy primer over urethane primer even though he has been in the business of painting cars 30 years. That is why I am asking.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-11-2012, 07:26 AM
Registered User
 
Last photo:
Join Date: Feb 2011
Location: Kalamazoo, MI
Posts: 1,113
Wiki Edits: 0

Thanks: 62
Thanked 94 Times in 79 Posts
You should have told him his entire existence in that company is utterly worthless then. That is one of the most basic things he should be able to answer. I'd see if you could talk to a different tech.

If it were me I'd probably block the 2k with 220 and put the epoxy down. The scratches are too fine to be revealed in the epoxy and epoxy lays down so smooth anyways as a sealer I shouldn't matter if you didn't go any finer than 220 below it. But I don't want to give you bad advice. I took some paint classes but only enough to be dangerous; I don't do this professionally.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 02-11-2012, 10:48 AM
Registered User
 
Join Date: Oct 2011
Location: Mo
Posts: 148
Wiki Edits: 0

Thanks: 0
Thanked 6 Times in 6 Posts
The data sheet for 491-10 says 320 grit, 491-16 is probably not much different. I don't really think you'll have any trouble, but I'm kind of curious why you didn't put the epoxy on first.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 02-11-2012, 01:25 PM
deadbodyman's Avatar
Registered User
 
Last wiki edit: Stripping paint Last photo:
Join Date: Feb 2009
Location: augusta,ga.
Age: 53
Posts: 6,081
Wiki Edits: 11

Thanks: 25
Thanked 443 Times in 372 Posts
Nason epoxy really kinda sucks as's.... I've used it ...You dont want to use that for a sealer...the 2k primer is pretty good and the paints not bad either when your on a tight budget....you would be better off not using a sealer at all just go straight from 2k sanded with 400 to paint...thier reducer sucks too,theres much better stuff out there at the same price...That work well...
I use a good bit of Nason products but some of it I wont touch...
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 02-11-2012, 06:53 PM
Registered User
 
Join Date: Feb 2012
Location: North Carolina
Posts: 18
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I looked at the sheet for Nason 491-10 but it was mixed 2:1 where the Nason 491-16 Epoxy I am using is mixed 1:1 so I did not think I was comparing apples to apples when it came to specs. The reason I did not spray the car with epoxy first is that when I sanded the car I only went to the factory primer and used epoxy on the locations where I broke through to bare metal. Then I read "the perfect paint job" on the SPI (Southern Polyurethane Inc.) web site. In my mind epoxy just seems to be the best and most stable surface for the topcoat. If there are drawbacks to using epoxy as a base for my topcoat, please let me know.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 02-11-2012, 07:11 PM
1ownerT's Avatar
Home School Valedictorian
 
Last wiki edit: Health and safety in the shop or garage Last photo:
Join Date: Dec 2004
Location: Iowa
Age: 53
Posts: 1,645
Wiki Edits: 4

Thanks: 0
Thanked 3 Times in 3 Posts
If I recall correctly, SPI recommends their epoxy reduced slightly as a sealer under the base coat.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 02-11-2012, 08:18 PM
Registered User
 
Join Date: Feb 2012
Location: North Carolina
Posts: 18
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Yes they do but I will be using the Nason epoxy not SPI (sticking to one brand for the entire project). Also I will be waiting about a month or two after spraying the epoxy before the car is painted with Nason Ful-Thane 2k Urethane Single Stage. I am doing everything except the final painting of the car, this is my first restoration.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 02-12-2012, 12:51 PM
Registered User
 
Last photo:
Join Date: Feb 2011
Location: Kalamazoo, MI
Posts: 1,113
Wiki Edits: 0

Thanks: 62
Thanked 94 Times in 79 Posts
I know it's the golden rule to stick to one brand for the entire process, but you would have been much better off going with the SPI epoxy over the Nason.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 02-12-2012, 06:16 PM
Registered User
 
Join Date: Feb 2012
Location: North Carolina
Posts: 18
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
When I do the next one I will be using SPI products. I know the process will go alot faster, I had to go slow and easy so as to not sand through the OEM primer to bare metal. Now I know to just take it to bare metal, spray epoxy, spray 2k urethane and start block sanding. I just wish that I hadn't waited until I was 50 to learn bodywork!
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 11-09-2012, 04:22 PM
Registered User
 
Join Date: Nov 2012
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Tech sheet

I'm sure by now you have sprayed the paint. I just finished spraying this primer and was considering just topcoating without sanding. Tech sheet recommends sanding with #400 or finer before topcoating with sealer.

Here is the link to the tech sheet if anyone needs it.

http://metropaint.com/pdfs/421-17_421-19.pdf

Ps. This is my first post I hope this helps.
Reply With Quote Quick reply to this message

Recent Body - Exterior posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Is wet sanding epoxy primer okay? Ripped Body - Exterior 9 04-25-2007 01:32 PM
can i spray epoxy primer over etching primer without sanding? wickiewicked240z Body - Exterior 1 08-29-2006 09:07 PM
What grit for epoxy primer? BIG DOG Body - Exterior 6 08-01-2006 09:23 PM
What grit do you sand epoxy primer before applying filler hemi43 Body - Exterior 8 01-24-2006 06:45 AM
Sanding with 80 grit question Skipr Body - Exterior 4 12-24-2005 10:45 AM


All times are GMT -6. The time now is 12:16 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.