Seam Repairs

[Miatatom]

Has anyone ever done a tutorial on repairing door/trunk seams? I'm building a 40 Ford and got a little careless and heavy handed rescribing the trunk seams. I'm looking for advice on fillers to use and techniques to make the repaired area look like right.

Edited May 9, 2021 by Miatatom

[Ace-Garageguy]

I have tried EVERY filler known to man.

The ONLY thing that has worked is West epoxy 105 with 205 hardener, mixed into a stiff slurry using microballoon.

See page three of this thread...and if you have any questions about getting the lines right again, just ask.

 

 

[Richard Bartrop]

I'm a big fan of using styrene to patch styrene whenever possible.  Work some Evergreen rod of appropriate size into the seam with a generous amount of liquid cement, then let everything set thoroughly.

[Richard Bartrop]

I'm a big fan of using styrene to patch styrene whenever possible.  Work some Evergreen rod of appropriate size into the seam with a generous amount of liquid cement, then let everything set thoroughly.

[NOBLNG]

18 minutes ago, Richard Bartrop said:

I'm a big fan of using styrene to patch styrene whenever possible.  Work some Evergreen rod of appropriate size into the seam with a generous amount of liquid cement, then let everything set thoroughly.

I agree, but evergreen rod might be softer than the original styrene. I haven’t tried the epoxy that Bill recommends, but I have made “sprue glue” using styrene chunks and liquid cement. Preferably use the sprue from the original kit if possible. Dissolve chunks of it in liquid cement until you have a thick paste. Fill the cracks and let it dry thoroughly. It may take a long time, (start another kit in the meantime) but when it is fully cured it will be just like the original plastic. Then the lines can be re-scribed. If you have an old scrap body...experiment a bit.

Edited May 10, 2021 by NOBLNG

[Miatatom]

2 hours ago, NOBLNG said:

Dissolve chunks of it in liquid cement until you have a thick paste. Fill the cracks and let it dry thoroughly. It may take a long time, (start another kit in the meantime) but when it is fully cured it will be just like the original plastic.

What do you use to make your paste in? There's always several builds going at the same time. 😀

[Plowboy]

I fill the panel line in with a strip of styrene the thickness of the line, sand smooth and rescribe. I have fixed small areas by filling with Tamiya Gray Putty and rescribe with a photo etch saw blade.

[NOBLNG]

10 hours ago, Miatatom said:

What do you use to make your paste in? There's always several builds going at the same time. 😀

Little jars that I got from Michaels.

[espo]

16 hours ago, Miatatom said:

Has anyone ever done a tutorial on repairing door/trunk seams? I'm building a 40 Ford and got a little careless and heavy handed rescribing the trunk seams. I'm looking for advice on fillers to use and techniques to make the repaired area look like right.

A question about your question ? Sounds as if you may have removed the body panel seem line in the body with excessive sanding of the body. 

[Miatatom]

59 minutes ago, NOBLNG said:

Little jars that I got from Michaels.

Thanks, I'll look for them tomorrow. 

 

17 minutes ago, espo said:

A question about your question ? Sounds as if you may have removed the body panel seem line in the body with excessive sanding of the body. 

The seam at the bottom of the trunk was super shallow. I slipped a couple of times and buggered it up trying to deepen it.

[espo]

1 minute ago, Miatatom said:

Thanks, I'll look for them tomorrow. 

 

The seam at the bottom of the trunk was super shallow. I slipped a couple of times and buggered it up trying to deepen it.

Been there done that and I'm wearing the T-Shirt.  Usually you can use a strip of masking tape as a guide and start to redefine the parting line with very light pressure on a #11 blade. Try not to cut to deep or fast until the line is straight enough to step up to a panel line tool or some sort of carving tool to match the present body lines. I had another modeler suggest to me that the tape like you would be used in the tool used to make plastic labels would work even better than the tape as a guide. 

[Miatatom]

13 minutes ago, espo said:

Been there done that and I'm wearing the T-Shirt.  Usually you can use a strip of masking tape as a guide and start to redefine the parting line with very light pressure on a #11 blade. Try not to cut to deep or fast until the line is straight enough to step up to a panel line tool or some sort of carving tool to match the present body lines. I had another modeler suggest to me that the tape like you would be used in the tool used to make plastic labels would work even better than the tape as a guide. 

My biggest problem is usually patience. I'll try the masking tape idea. The only problem I've found with the label maker tape is it only works on straight lines.

[Bainford]

This is another option for scribing tape 

[Ace-Garageguy]

Far as re-scribing technique, I'll give my own insight.

First, I'll assume you want to get lines that are supposed to be straight lines straight, and corners and curves with nice clean radii.

Nothing detracts from a model like wonky scribing.

For STRAIGHT lines, I'll use a self-adhesive tape product as a guide...something like Dymo label-making tape, or heavy 3M aluminum aircraft tape.

I find the HARD edges afforded by these materials are vastly easier to follow than soft masking tape...unless you're really an old hand at scribing.

The temptation for most folks is to use too much pressure initially, and that will surely get you into the real estate surrounding a masking tape guide.

A HARD edge just works better.

For curves, rounded corners, and other non-straight lines, there are lotsa scribing guides on the market.

These are generally photo-etched rectangles of metal with various openings with a variety of curves. They look like draftsman's eraser-shields from long ago.

       

You securely tape the guide to the work, and scribe through it.

As stated elsewhere, start very lightly, and make as many passes as you need to to achieve the required depth.

I also do NOT recommend the old "backside of a #11 blade".

You want something made for the job, that will take a very thin "curl" out of the groove, rather than having the tendency to widen the scribe as you go deeper like the old #11 blade will.

I HIGHLY recommend these scribing tools from Tamiya. My scribing work has improved to the point I'm very happy with it since purchasing and mastering them.

Folks complain about the expense, but if you want to do quality work, there's no substitute for good tools.

 

[espo]

1 minute ago, Miatatom said:

My biggest problem is usually patience. I'll try the masking tape idea. The only problem I've found with the label maker tape is it only works on straight lines.

If you're working on a bend or corner you could try some thin fine line tape and build it up with a second layer of heavier tape. I don't have any patience either, but slow and steady is better than trying to fil the lines you cut into the tape or off into the body. I have done that and no mater how hard you try the blade wants to follow your mistake instead of your intended line.  

[Ace-Garageguy]

Aircraft modelers tend to be a little more quality-focused than the general herd. 

Here are some more recommendations...

https://forum.largescaleplanes.com/index.php?/topic/29897-re-scribing-panel-lines-what-tools-do-you-use/

[Ace-Garageguy]

 

[Tom Geiger]

My big issue is scribing the panel line through putty.  On my Valiant Speedster I had to scribe the back hood line and tops of the doors through the areas where I had put together the pieces from two different bodies. 

No matter what I used, my scriber  or exacto blade, the edges of the putty would crumble rather than cutting cleanly. I just kept reapplying putty into the seam and trying again until I got an acceptable result. Still not perfect.

 

[Ace-Garageguy]

2 hours ago, Tom Geiger said:

My big issue is scribing the panel line through putty.  On my Valiant Speedster I had to scribe the back hood line and tops of the doors through the areas where I had put together the pieces from two different bodies. 

No matter what I used, my scriber  or exacto blade, the edges of the putty would crumble rather than cutting cleanly. I just kept reapplying putty into the seam and trying again until I got an acceptable result. Still not perfect.

 

And that right there is why I recommended the West epoxy and microballoon mix I use.

The thread I linked to shows two perfect scribed lines very close together.

NOTHING else I've tried would allow that kind of result.

[Miatatom]

42 minutes ago, Ace-Garageguy said:

And that right there is why I recommended the West epoxy and microballoon mix I use.

The thread I linked to shows two perfect scribed lines very close together.

NOTHING else I've tried would allow that kind of result.

I've got some BSI 5 and 30 minute epoxy and a big ol' bag of microballoons. Think that'll work?

3 hours ago, Tom Geiger said:

My big issue is scribing the panel line through putty.

No matter what I used, my scriber  or exacto blade, the edges of the putty would crumble rather than cutting cleanly. I just kept reapplying putty into the seam and trying again until I got an acceptable result. Still not perfect.

I keep running into that problem. 

[Ace-Garageguy]

38 minutes ago, Miatatom said:

I've got some BSI 5 and 30 minute epoxy and a big ol' bag of microballoons. Think that'll work?

The 30-minute's worth a shot.

But here's a secret not many folks seem to know.

THE LONGER any epoxy takes to cure, THE STRONGER it usually is.

You can't sand or scribe the West stuff I recommend for 12 hours.

And it works, as my photos show.

[NOBLNG]

6 hours ago, Miatatom said:

My biggest problem is usually patience. I'll try the masking tape idea.

You WILL need patience while waiting for sprue glue to cure, if that’s the route you go.

[Tom Geiger]

2 hours ago, Miatatom said:

I've got some BSI 5 and 30 minute epoxy and a big ol' bag of microballoons. Think that'll work?

I keep running into that problem. 

I found that the BSI CA glues sanded at a different rate than the putty / styrene around it.  I just made a mess of it.

[peteski]

2 hours ago, Tom Geiger said:

I found that the BSI CA glues sanded at a different rate than the putty / styrene around it.  I just made a mess of it.

Any CA glue goes from softer than styrene, to harder than styrene as it cures.   If you sand it few minutes after it cures, it will still be soft and gummy.  But if you wait for 12 hours, it will be harder than styrene.  Best is to let it set for few hours before sanding, but not to wait til the next day.