Can you put filler over self-etching Primer? Safely - 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 07-27-2007, 03:59 PM
Registered User
 
Last photo:
Join Date: Oct 2005
Location: San Antonio TX
Age: 49
Posts: 156
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Can you put filler over self-etching Primer? Safely

Guys,
I have a really really small spot I need to re weld and the do the works on it. I dont fee like mixing my 2k primer just for a quick squirt, so I have a can of self etching primer the local jobber sold. Can I just put that over the bare metal and then use my rage filler over it safely? I mean this is a really really small weld section I did. What do you think?


MP
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 07-27-2007, 05:20 PM
Holder350's Avatar
Auto Parts Professional
 
Last photo:
Join Date: Feb 2005
Location: Whitesburg, TN
Posts: 1,037
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Are you going to put plastic body filler in it? if so it will do better to apply it directly to the bare metal....it doesnt adhere to primer to well. then after you get it on and filed down spray your selfetching primer over it
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 07-27-2007, 05:36 PM
Registered User
 
Last wiki edit: Mopar tapered axle rear brake conversion
Last journal entry: What I'm doing now...
Last photo:
Join Date: Jan 2002
Posts: 4,267
Wiki Edits: 49

Thanks: 0
Thanked 4 Times in 4 Posts
As long as you let the primer fully cure and then scuff the surface it will be fine. As a matter of FACT body filler works better when applied over a protective primer (epoxy or self etching) simply because the primer helps protect the bare steel from moisture. Body filler is extremely porous and will absorb moisture just from the air. That moisture can then attack the underlying steel if its not protected with a good quality primer. It would be better to use an epoxy primer but self etching will work fine. It's just yesterday's technology.

Good luck.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 07-27-2007, 06:14 PM
Registered User
 
Last photo:
Join Date: Oct 2005
Location: San Antonio TX
Age: 49
Posts: 156
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
went with the 2k

I decied to mix up some 2k primer after all. I went aheed scuffed my metal with 50 grit shot two coats of 2k primer on it let it sit for a while and drove the truck to get my boys. I'm going to wait another 2 hours then put down some evercoat rage of the 2k primer. I guess I did not want to chance it. But thanks guys.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 07-27-2007, 06:23 PM
Holder350's Avatar
Auto Parts Professional
 
Last photo:
Join Date: Feb 2005
Location: Whitesburg, TN
Posts: 1,037
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by Centerline
As a matter of FACT body filler works better when applied over a protective primer (epoxy or self etching) simply because the primer helps protect the bare steel from moisture. Body filler is extremely porous and will absorb moisture just from the air.
Centerline, isnt primer porous also? which is the reason that old school rodders add about a quart of black enamel with black primer to paint rods with and it infact seals the metal from being exposed to moisture? I may be wrong but its just what I'v always heard.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 07-27-2007, 06:29 PM
Member
 
Last photo:
Join Date: Feb 2003
Posts: 642
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
you will be able to tell when you sand your filler if its gonna stick or not.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 07-27-2007, 09:08 PM
Member
 
Last photo:
Join Date: Nov 2003
Location: Green Bay, WI
Age: 43
Posts: 2,073
Wiki Edits: 0

Thanks: 0
Thanked 5 Times in 5 Posts
Only primer that is non porous is epoxy primer. As far as recommendations, epoxy can have filler applied over, I was always taught to use in moderation of urethane primers, 2k spot type fillers supposedly okay to use withen reason over sanded urethane primer or paint. Not suppose to use regular filler over urethane or paint, but I've done small spots over sanded urethane with regular filler without any seeing any apparent problems pop up from it. Many self etching primers have strict warnings about applying over bodyfiller or applying bodyfiller over it, but think most have agreed on here if you allowed quite awhile where acid would no longer effect it would be okay. But don't think if you got a break in the paint film which allowed moisture to reach the filler, filler to soak it up, that self etching or even urethane for that matter would do anywhere near the job epoxy would preventing it reaching the metal underneath. I believe back when lacquer primer was what was used, they kinda advised against wetsanding it, and likely due to reaching metal underneath.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 07-27-2007, 09:33 PM
Registered User
 
Last wiki edit: Mopar tapered axle rear brake conversion
Last journal entry: What I'm doing now...
Last photo:
Join Date: Jan 2002
Posts: 4,267
Wiki Edits: 49

Thanks: 0
Thanked 4 Times in 4 Posts
Quote:
Originally Posted by Holder350
Centerline, isnt primer porous also? which is the reason that old school rodders add about a quart of black enamel with black primer to paint rods with and it infact seals the metal from being exposed to moisture? I may be wrong but its just what I'v always heard.
Ol school methods (back in the lacquer days) required that. Now days with epoxy primers that's not necessarily the case. Modern filler primers are porous so you wouldn't want to use one of those but the majority of pros today recommend filler over cured epoxy primer to protect the bare metal from moisture.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 07-27-2007, 10:06 PM
crashtech's Avatar
Technician
 
Last wiki edit: Epoxy primer
Join Date: May 2005
Location: Idaho
Posts: 701
Wiki Edits: 17

Thanks: 0
Thanked 0 Times in 0 Posts
Would I put plastic filler over self-etching primer? NO. Not ever.
Would I put plastic filler over partially cured 2K urethane primer? NO. It should be fully cured and sanded to apply plastic filler, even then this is not optimal.

Plastic filler is best applied over epoxy primer 24-72 hours after it is shot, depending on brand and temps. Next best is freshly ground, sanded, or sandblasted metal that is totally free of porosity, rust, or holes.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 07-28-2007, 06:42 AM
wedgehead63's Avatar
Registered User
 

Last journal entry: New Attitude
Last photo:
Join Date: May 2007
Location: Auburn Ky
Posts: 48
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I'm with you crashtech. I have been made a believer time and time again by the bond between filler and epoxy primers. I was taught to only use plastic filler on ground bare metal. That still works great, but those were the days before epoxy. By the way, I have been trying a product from SEM called METALOCK. It is two part epoxy that has filling and sanding properties of a 2k urethane. I have used SEM dyes and flex additives for years. It seems like a great product so far.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 07-28-2007, 08:23 AM
Member
 
Last photo:
Join Date: Jan 2005
Location:
Posts: 3,707
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by crashtech
Would I put plastic filler over self-etching primer? NO. Not ever.
Would I put plastic filler over partially cured 2K urethane primer? NO. It should be fully cured and sanded to apply plastic filler, even then this is not optimal.

Plastic filler is best applied over epoxy primer 24-72 hours after it is shot, depending on brand and temps. Next best is freshly ground, sanded, or sandblasted metal that is totally free of porosity, rust, or holes.
Exactly, I totally agree. Do not put polyester products over self etch 1K primers!
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 07-28-2007, 08:30 AM
Member
 
Last photo:
Join Date: Jan 2005
Location:
Posts: 3,707
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by wedgehead63
I'm with you crashtech. I have been made a believer time and time again by the bond between filler and epoxy primers. I was taught to only use plastic filler on ground bare metal. That still works great, but those were the days before epoxy. By the way, I have been trying a product from SEM called METALOCK. It is two part epoxy that has filling and sanding properties of a 2k urethane. I have used SEM dyes and flex additives for years. It seems like a great product so far.
A good friend of mine is also testing the SEM metalock primer in collision repair conditions and so far he reports many of the shrinkage problems he seen with other products has gone away. I haven't used the stuff but imagine it must be an epoxy hybrid like PPG's old NCP-270 which was OK but didn't offer as much corrosion resistance as a true quality epoxy.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 07-28-2007, 08:38 AM
Member
 
Join Date: Jan 2004
Location: Overland park, Kansas burb of KC
Posts: 244
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by crashtech
Would I put plastic filler over self-etching primer? NO. Not ever.
Would I put plastic filler over partially cured 2K urethane primer? NO. It should be fully cured and sanded to apply plastic filler, even then this is not optimal.

Plastic filler is best applied over epoxy primer 24-72 hours after it is shot, depending on brand and temps. Next best is freshly ground, sanded, or sandblasted metal that is totally free of porosity, rust, or holes.
100% agree.
If I did need to apply filler over urethane it would be a poly glaze rather then regular filler and only a very thin skim coat.

Bob, does PPG not sell/make the NCP270 anymore? That was a HUGE product for them a few years back.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 07-28-2007, 12:57 PM
Member
 
Last photo:
Join Date: Jan 2005
Location:
Posts: 3,707
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Eric, Last I heard PPG was phasing out the NCP270 and this was a few years ago, I'm not sure if it's available now. Stinky stuff
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 07-28-2007, 06:57 PM
wedgehead63's Avatar
Registered User
 

Last journal entry: New Attitude
Last photo:
Join Date: May 2007
Location: Auburn Ky
Posts: 48
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Hey Bob, It's been a while since I used that PPG product(1997), and I think I can still smell that s**t! It is truely a unique funk. It stunk just as bad when you sanded it. I liked the product, but I won't miss the stinch!
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: 2 (0 members and 2 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
epoxy or etching primer over bare metal? pineknot Body - Exterior 21 03-16-2007 07:53 PM
Non etching primer or epoxy Skipr Body - Exterior 9 12-01-2005 10:21 PM
Fiberglass Hood, Etching Primer? Custom95Z Body - Exterior 21 08-25-2004 12:48 PM
Do you need etching primer under featherfill primer? Fordy8man Body - Exterior 14 10-29-2003 07:23 PM
etching primer readyeddie Body - Exterior 9 10-20-2003 10:02 PM


All times are GMT -6. The time now is 12:26 PM.


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.