Fresh Base reacting with old base on spot repair - 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 03-18-2005, 07:40 PM
Have Gun, Will Paint
 
Join Date: Nov 2003
Location: Washington State 509
Age: 35
Posts: 208
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Fresh Base reacting with old base on spot repair

I'm doing a spot repair on a hood.

It had a deep scratch wich I scuffed, then filled with glazing puddy......block sanded smooth

Started the blending prosess with grey k2 urethane sealer.........and thats when I notice the paint under neath reacting with the sealer.........it seemed to "crack".......and by the looks of it, it's only were the base underneath is peeking through the sanded clear.

I sanded again, and this time I skiped the sealer, and tryed blending the new base color striaght.........it did the same thing.......

How can I provent the old exposed base underneath from reacting with the fresh paint, with out having to sand the whole panel down to the OG primer?

I'm almost positive, it's the reducer in the new base that is reating with the old base..........In one last attemp I used fast reducer, and misted the first 2 coats on lightly........wich seemed to work, but as soon as I put on a medium coat, it did it again

Any sugestions?
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-18-2005, 08:04 PM
Have Gun, Will Paint
 
Join Date: Nov 2003
Location: Washington State 509
Age: 35
Posts: 208
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I'v ran into this problem befor, and I'v always had to sand down past the base and start from there....(wich I'll probably be doing again with this one)

but there has to be some kind of primer or sealer I can apply as a ground coat that won't react to the exposed base

what about an epoxy sealer?

I'v also tried a k2 serfacer in the past, but with the same reaction.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-18-2005, 08:46 PM
Member
 
Join Date: Jan 2005
Location: Napoleon,MO.
Age: 46
Posts: 148
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
From my past experience, scuffing then glazing a scratch is a bad thing to do. Unless the car has a ton of paint on it, sand the scratch out and prime. If you use glaze use one that has a hardener then prime. I know this wasn't part of your question but had to give my opinion on that.

OK, we need to know what is on the hood. Factory paint, a repair or new paint. Could it be lacquar? What is it, very important!! Sounds really weak and you are right, it is the reducer that is causing the lifting. It has been years since I've had a lifting problem. Rarely(in my situations) have I had a 2K surfacer cause lifting. Actually, I can think of only one time and that was on a repair of a custom marblizer that I had head up *** and ran my primer. Now I'm a collision painter and I do some custom work and I use only the best brands(not saying you don't,just keep reading) so if you use some "off" brand paint I'm not familiar with them. The best brand paints have their own "off" brands and I have little experience with them too. So please tell us what you are spraying over and what you are spraying on and the guys/gals on here will hopefully hook you up.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-19-2005, 03:19 AM
Have Gun, Will Paint
 
Join Date: Nov 2003
Location: Washington State 509
Age: 35
Posts: 208
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
This was suppose to be a "quick fix" for a buddy of mine........wasn't going to charge him anything, and it was also suppose to be in one day and out the next.

I've been painting for several years now, mostly custom refinishing. HOK and Dupont Chroma series for the high end stuff, and Dupon Nason for the low end stuff...........which is what I used here...(Nason)

The paint looks like it has a metallic urethane bc/cc over the factory paint......so it has been painted before and not that long ago.......I say about late last fall or early this winter.

The scratch or should I say "gouache" was caused by a key or most likely a screwdriver, and it runs right down the middle of the hood. (a friendly gesture by an admirer, I'm sure )

I have not used any 2k surfacer on this particular repair, but like I said I've had this problem before, though rarely (I can count them in 1 hand), and always during a spot repair were the old base had been exposed during block sanding.

Like I said, it is suppose to be a quick fix, glazing putty I used was a 2 part polyester from evercoat, and isn't causing any problems.

I've since resanded the area, and plan to try again tomorrow before I have to DA it all down to factory ground coat and start all over, which means I will have to color blend into the fenders for the color match (so much for a quick fix) something I don't look forward to.

I'm thinking of picking up some epoxy sealer and trying that?

Thanks for the reply AC/DC
any more recommendations would be appreciated
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-19-2005, 05:37 AM
theHIGHLANDER's Avatar
Member
 
Last photo:
Join Date: Feb 2005
Location: S.E. Mich
Age: 56
Posts: 214
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
If you're using a reactive reducer, or a basemaker that's most likely key to the problem. The glazing putty, primer, and sealer with their related solvents has softened up the refinish base. You sound like you been doing this work for a while so a quick fix soution may be in order.

Trick the existing base into drying by warming it up and cooling it down. Warm it slightly again, then apply the new base gently so it flashes before it can lift. I know the logistics of this wreak havoc on match but you very well may pull it off. I suppose you need to see if the clearcoat will lift it too. I general, filler over re-finish mat'l keeps the stuff underneath soft and wll always give a raised ring around the repair.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-19-2005, 05:44 AM
Member
 
Last photo:
Join Date: Apr 2004
Location: Georgia
Posts: 3,573
Wiki Edits: 0

Thanks: 10
Thanked 57 Times in 36 Posts
If you knew up front a potential problem.

Epoxy, waterborne primer would have worked.
At this point you have a 70-80% chance the above will keep it down.

Only thing that will work at this point is "Bar coat" made by upol an alcohol base sealer about $18 a quart.
If jobber does not have it he can have it from any warehouse he buys from next day.

PPG jobbers usually stock it because they have re-coat problems with omni.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-19-2005, 10:52 AM
Have Gun, Will Paint
 
Join Date: Nov 2003
Location: Washington State 509
Age: 35
Posts: 208
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks for the replies guys.........I talked to my buddy this mourning, and he said just repaint the entire hood, and not worry about the color match.........that does make things easer for me, I'll just sand down to the factory ground coat and work up from there.........but I won't feel at ease if that hood would too stand out from the rest of the finish because of bad color match.

I was still going to give an epoxy sealer a try first, but this "bar-coat" sealer sounds interesting.....

Do you have more info on this sealer Barry?
How it lays down, will it need mixing or is it just a pore and spray sealer?

Thanks again guys
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-19-2005, 03:57 PM
Bee4Me's Avatar
Problem Child,Hard Case
 

Last journal entry: Strangest job I've ever done
Last photo:
Join Date: Jan 2005
Location: ARK.
Age: 57
Posts: 1,773
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
With the small amount of time passing since the 2nd paint job,I would think you have a better than average chance of getting a deicent color match as long as you don't get an old can of the Nason.
If you have the time,Let the first coat of base cure out good,scuff and reshoot the base,wait as long as possiable then clear.Might just hang in there for you.Rember that Nason IS an enamel of sorts (thanks Barry) and you know what enamel does if it's not dried out GOOD before recoating.(wrinkles/lifts like crazy.)
Good Luck.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-19-2005, 04:12 PM
p8nter's Avatar
Member
 
Join Date: Mar 2005
Location: Missouri
Posts: 62
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Why not just prime it. sealers have a higher solvent content and don't do to well fixing lifting and swelling problems. Filler primers are so high solid,the solvents don't penetrate as deep.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 03-19-2005, 04:18 PM
Member
 
Last photo:
Join Date: Apr 2004
Location: Georgia
Posts: 3,573
Wiki Edits: 0

Thanks: 10
Thanked 57 Times in 36 Posts
[ but this "bar-coat" sealer sounds interesting.....

Do you have more info on this sealer Barry?
How it lays down, will it need mixing or is it just a pore and spray sealer?

Thanks again guys[/QUOTE]
*************************************************
Its already mixed, only precaution is its thin and not made for filling flaws.
Spray one coat NEVER two coats and wait about 30 minutes and prim or paint.

I saw a black Yukon in Mobil, Al about a year ago, hail damage and they sprayed ppg on it had flaws and when they went to get in it it would bust, so PPG rep says bar coat and he came and sprayed it Three coats!
I saw the truck a month later when it was coming off in sheets.
The stuff is to tight and will trap solvent if more than one coat is applied.

bk
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 03-19-2005, 07:46 PM
Have Gun, Will Paint
 
Join Date: Nov 2003
Location: Washington State 509
Age: 35
Posts: 208
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Like I said before.......this was suppose to be a freebie quick fix....

The scratch was thin but deep (like a groove)....I scuffed the surrounding area and cleaned out the groove. Filled it with polyester glaze, and block sanded it smooth with 400.

When block sanding, some of the clear around the area was stripped exposing the base underneath.

I continued by scuffing the whole hood with a gray scuff pad.....

I then applied 1 wet coat of sealer over the repair, and planned on color blending the base on to the rest of the hood then clearing the entire hood, but the old exposed based reacting with the sealer.......and sanded off the sealer (and more clear went with it). Tried again, and this time I skipped the sealer and just went with straight base, but still it reacted....I stopped right there and called it a day.......I didn't try a urethane serfacer because I have had it react in the same way in the past.

Today I just got out the DA and sanding the entire hood down to the factory ground coat, then block sanded with 400.......shot the sealer followed by the base and clear.......No problems....but the color match is slightly off, most people probably wouldn't tell innless looking at it closely, but oh well.

What was suppose to be an freebie overnight quick fix, turned out to be a 3 day job and my pal owes me a "carne asada" lunch with the homies next weekend


Still I would like any impute on avoiding this problem again in the future, and if anybody knows exactly what is causing it and why

And thanks again for all your input

Alex.S
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 03-20-2005, 08:07 PM
Bee4Me's Avatar
Problem Child,Hard Case
 

Last journal entry: Strangest job I've ever done
Last photo:
Join Date: Jan 2005
Location: ARK.
Age: 57
Posts: 1,773
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
No good deed goes unpunished.

Hopefully the grub and following "beverages" will make up for it.

I'd be REAL interested in WHAT product/s were used on the previous paint job. They were obviously the problem as you were doing everything right and no matter what you did,nothing was going to mix with it.
Could have been lousy or little prep of the OEM paint and the 2nd job was just "laying" on top of it.
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
"Basic of Basics" Welding - How do I repair body panels? Centerline Body - Exterior 33 03-31-2014 09:45 AM
Ignition timing advance question. Terje Engine 14 07-31-2004 04:03 PM
Spot repair question Dbodily Body - Exterior 3 05-12-2004 10:32 AM


All times are GMT -6. The time now is 07:13 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.