How to Remove "Ghost Trim"

[diymirage]

hey guys

ive been using the bondo glazing putty for some minor body work and i really like the way it handles

the only thing i dnt like about it is the way that it will ghost with some paints

(i dont have a picture right now but a great example is a hood where i filled in the holes with styrene, smoothed it out with the putty but after paint it still shows the outline of the hole in a different shade)

what do you guys use for a sealer ?

[DRG]

Great question I have had the same problem.

[Marc @ MPC Motorsports]

You will have this problem with any solvent-based filler. The solvents in the paint will react with the filler causing the ghosting.

[diymirage]

You will have this problem with any solvent-based filler. The solvents in the paint will react with the filler causing the ghosting.

if i would put a coat of clear over it before laying down the base would that seal it ?

[Cato]

if i would put a coat of clear over it before laying down the base would that seal it ?

A coat or two of Future on the putty will form a barrier.

Edited November 26, 2010 by Cato

[MikeMc]

Use duplacolor primer / sealer or future.....Thats why you need the 2 part

[Mike Kucaba]

I use DuPont Vari-prime. There are other factors that cause ghosting.e.g. solvent glues,crummy styrene, and the lacquer primer itself.Other solutions I've heard of are B-I-N pigmented shellac(white) and a coat of Future,and a coat of liquid glue(like Tenax).

[MoparWoman Jamie]

A coat or two of Future on the putty will form a barrier.

I'll 2nd that.

That is what I always do.

[diymirage]

A coat or two of Future on the putty will form a barrier.

how long do you wait in between the coats ?

(and since were on the topic of future) if you use it as a clear coat can you polish it ?

[MoparWoman Jamie]

how long do you wait in between the coats ?

(and since were on the topic of future) if you use it as a clear coat can you polish it ?

How long in between coats? well I can't answer for the other person, but for me, the stuff drys very nice and quick. I would say maybe 20 to 30 minutes if that as that is how long mine takes to dry.

About the polishing part, I heard people say you couldn't but yet I have tested that out with some plastic sheet color like I would paint a model and then after the future dried I took one kind of polish that I have here and I manage to get the stuff to work as the stuff came out shiny where I could see my reflection in.

[Cato]

...I can't answer for the other person, but for me, the stuff drys very nice and quick. I would say maybe 20 to 30 minutes if that as that is how long mine takes to dry.

As the 'other person' in your life I agree that a 1/2 hour is an adequate time. I prefer to let it dry several hours to a day. The longer time for finished parts (like clear glass) or top coats. Never have a problem that way. I always find 100 other things to build, prepare, mock-up so it doesn't slow up progress on the build for me to wait longer.

I do not polish Future as I prefer polishing kits on the paint or clear coats.

[Chuck Most]

I've never tried Future, but I can vouch for Duplicolor primer sealer, and BIN sealer. Both do a great job preventing ghosting on 2-part putty.

[crazyjim]

Will a coat or 2 of Future over the final primer also eliminate ghosting from removing emblems, door handles, etc. before painting. Never had the problem with Testor's, but now that I've switched over to HOK paints, I get ghosting.

[Guest Sickfish]

It should, but Bill Geary clued me into the best way to eliminate ghosting when you remove such things. Once removing them, & before applying any putty, primer or paint, brush on a coat or two of a liquid cement like Ambroid Pro Bond or Tenax 7R over the area & let dry. Once it's dry, sand it down well, & then apply putty if needed. The liquid cement is as hot a solvent as any paint

or primer you'll use, so it acts as both a barrier against the

paint solvents, as well as already bringing up the ghosted

image of the removed emblem with the liquid cement, which you subsequently sand down & eliminate after the cement dries.

Easy technique & it works like a charm! I do it a lot. It also comes in handy in eliminating seams.

I have to agree with this technique

on my current project, 06 Charger Superbee, I glued the gas-tank lid in place & used 1 part auto putty to fill it in. After drying & sanding back I applied some superglue over the whole area & did the same. I then primered over & have now colour coated over the area without any ghosting ! I've done this with enamels, auto paint & lacquers ( HOK ) & all came out without any sign of ghosting 

Cheers Cliffo 

[Bruce Poage]

Working on '57 Chevy 1/2 ton. I wanted a clean hood look. Thus I sanded the ridges that have a chrome spear point in the front. The hood is smooth. I shot and sanded Dupli-Color white primer as usual and it all looked good. That followed several coats of Krylon Iris and clear. As I buff out the paint is see the outline of the "bumps" I had removed. Somewhere I read info that when removing molded trim from a body a ghost of that trim may reappear. The article contained a solution. I am clueless about where I read this article. Can anyone pass along hints regarding how to take care of this ghost. Thanking you as always.

[rustbucket82]

I use Tamiya Extra thin cement. Comes with a brush, I brush the cement over where the trim was and it caused the "ghost" to show up. Sand, repeat until you no longer see it pop up.

[my80malibu]

I think bill geary said liquid cement swells the plastic and helps to eliminate the ghosting

[Mike Kucaba]

Another trick to try if all else fails is to actually gouge out the area and fill with your favorite putty, maybe even go so far as to place some plastic scrap in the gouge and sand flush. Ghosting is a perplexing problem and crops up now and then ,and sometimes it can just be the way the plastic was formulated at the time.

[Art Anderson]

Another trick to try if all else fails is to actually gouge out the area and fill with your favorite putty, maybe even go so far as to place some plastic scrap in the gouge and sand flush. Ghosting is a perplexing problem and crops up now and then ,and sometimes it can just be the way the plastic was formulated at the time.

I've had considerable experience with "ghosting", given that I started using automotive acrylic lacquers to paint model cars over 40 years ago; so here's my read:

Styrene plastic is easily penetrated by so-called "hot" solvents such as liquid cement and lacquer thinners of all kinds--this is what causes solvent-based plastic cements to melt and "weld" two plastic parts together, but lacquer thinners (and even some of the solvents used in enamel paints as well) also do this, generally to a lesser extent. Complicating this is the process by which model car kits are molded--molten styrene plastic is forced into the molds for a model kit under tremendous pressure (generally 80-100 tons per square inch) which, as the plastic cools and solidifies, locks in a lot of stresses in the finished parts. When lacquers (be they automotive acrylics or even the so-called "non-penetrating" thinners in such as Tamiya or Modelmaster lacquers) are sprayed on a model kit body, they tend to "relieve" some of those stresses--notably around mold parting lines, but also in places where raised details have been removed. But, what to do about it?

This is where a good primer comes in, in my experience. Lacquer primers will relieve those stresses, making parting lines tend to "ghost out", and certainly where any raised detailing has been sanded, carved or otherwise shaved off. A coat of a good lacquer primer (automotive IF the final finish is to be automotive, otherwise Tamiya lacquer primer) sprayed on, and allowed to dry thoroughly overnight, followed by a light sanding over the ghosted area will smooth it down. A second coat of primer will show whether or not the ghosting has been removed, and if not, repeat the process. Ultimately, you should be able to put the final finish color down with no further hits of ghosting. I submit as well that it goes without saying that this is one of those things for which an airbrush is ideal--as that allows one to correct ghosting which happens generally in relatively small areas without creating a thick buildup of the primer in areas where there isn't such a problem.

Art

[Ace-Garageguy]

I removed the raised accent line from the center of the decklid on a '70 Chevelle contest model, coated the area with liquid cement, blocked it flat 2 days later, primered it with high-build Duplicolor primer, 2 coats and allowed to dry a week. Blocked flat again and 2 more coats of high-build, dried for a week and blocked. 2 more coats, dried for 2 days and blocked. One coat of sandable white Duplicolor, dried one day and scuff sanded.

5 coats of Testors One-Coat lacquer, followed by three coats of Testors Wet-Look clear, sanded wet from 3500 to 12,000 grit, polished with 3M Perfect It machine polish, by hand.

It looked absolutely perfect when finished. Now, about 13 months later, I can see the ghost of the old line in the reflection from certain angles.

[Mike Kucaba]

The only primer I ever found that truly blocks ghosting is DuPonts Vari-Prime. It did fail me once on the new tool '62 T-bird where I tried to remove the side trim, and even gouging it out and filling with plastic and using CA glue and two-part putty it just kept ghosting back. Bought another kit and prepped the body similarly an no ghosting. Go figure. Bad plastic formulation?

[Guest]

Brush a coat of future over your removed trim/scripts before primer. Future will seal the plastic and won't allow the primer to penetrate and make the details swell. Or.. you can spray Plasi Kote sandable primer in light coats and not have the problem at all.

[bad0210]

It seems i sand them off. But after i finish painting the paint looks perfect until i clear coat and it fully dries. Then the lines start ghosting back. I tried primer sealer but it still happens. The paint i use is duplicolor primers and basecoats. This last time i used duplicolor primer sealer over the primer before the base coat.

[bad0210]

I'll try that. Thanks!

[StevenGuthmiller]

More Primer!! I've come to the conclusion over the years that the more primer the better, especially when you're dealing with automotive lacquers. I usually use a good 4-6 coats of primer. That may be a bit of over kill, but I'd rather be safe than have things start etching on a rare vintage kit or the like. Keep in mind also that Duplicolor primers are a bit hot themselves & will etch the plastic themselves if sprayed too heavily initially. I start with a couple of light mist coats, & then spray successively heavier coats as I go. I haven't had any "ghosting" problems with the mold lines since I started using more primer coats. You can spray a lot of Duplicolor primer without having to worry about covering any detail. Steve