Fixing panel line messes

[badlandsghost]

Hey folks. Been a while, but its been a rough decade-ish.
So anyway, i have the older 1/72ish slave 1 that i got many moons ago. At the time i was feeling really optimistic, and decided to ditch the raised panel line for scribed. (An example of why i try not to be optimistic).
The scribing job i did isnt really bad, but its not crisp at all.it was done w picks along the raised lines, but still looked bad enough to go back into the "later" pile.
Anyway, looking for ideas on how to clean it up so i can finish the damn thing.
I was thinking label tape borders w water soluble putty, and then just re digging em, but wanted to know how others have dealt w this kind of thing.
Thanks,
J

[Rogviler]

I prefer filling with CA glue and re-scribing. Mainly because CA is hard so it's going to be a nice crisp line. Which is the problem with some putties, they can flake off or they're so soft that the scriber just wants to follow the old line.

Other options: Fill with stretched sprue or sprue goo, which would essentially rebuild the original plastic. Fill with Aves Apoxie. Again, this is nice and hard so it's easy to get good lines in it. Both of these take awhile to dry though, which is why I prefer the CA glue.

[Lt. Z0mBe]

Place a drop of Loctite CA on a palette. Dip the tip of a straght pin into the droplet and then walk the drop along the failed line using the straight pin. Allow to dry for five or 10 minutes. View your sanding/scribing process in relief via using a light source opposite of your face with the subject in the middle. Check from both sides by rotating the piece in your hands so that flaws not seen from one side will be seen from another. Wet sand the CA with 220-grit wet-dry paper, protecting clear parts and details wih masking tape then scribe.

Since it’s 1/72 scale, scribe regular panels with sharpened straight pins or .010 scribing saws, and control surfaces and hatches with a pick or scribing saw of .015in. These will scratch the cured CA (or virgin plastic) instead of plowing through it, giving you a sharper line. For guides, I use Dymo label tape, or doubled masking tape, or taped on scribing guides, or handheld guides, or handheld/taped 3.5-inch floppy disk metal sliding things, or custom cut .015-inch styrene for complex shapes. Sometimes, I free hand it too over short distances. I also use various thicknesses of scribing saws, gravers engraving tools, pins, needles, bone picks, old razor saws, dental picks, machinist scribes and whatever else I need to get in-scale, “weighty” panel lines. I build mostly aerospace fighters and take scribing verrry seriously.

I recommend CA or Aves, depending upon how much area you’ll be filling, Bondo from the tube works great too, but you may want to varnish it with CA before scribing. Mr Surfacer works well too, and it’s harder and less flaky than the Bondo, but takes a long time to cure to the maximum hardness you’ll want for scribing. With the Aves, it takes a delicate touch with pins and the like, as it is a little more crumbly than styrene or CA, behaving a little like a candle when something sharp is pressed into it. Bondo is even more crumbly, and benefits from a very light touch. Push too hard and you’ll end up with a plowed jagged garden row with a wide, deep beginning and/or end. With scribing saws, it’s not as bad with the Aves and Bondo, by the way but it’s still easier to screw up than cured CA. Mr. Surfacer, cured, is almost as good as CA, being more “scratchable,” and less crumbly, than Bondo and on par with Aves. I would avoid the water-based putty for this application, as it’s basically thick acrylic paint and thus has no chemical hotness with which to gain tooth on the plastic and will pop right out of the failed panel lines like old caulk being removed from old bathroom tiles. Also, be careful using Dymo tape over Aves and Bondo, as it loves to rip them up and destroy the feathered edges of filled areas

When you’re all done and prior to priming, lightly wet sand all the scribed areas with 400- or 600-grit sandpaper, proceeding to polish if necessary. This will sharpen the edges of the scribed lines, making them look closer to 90-degree scribes and less like they’re V-shaped. Blow out the sanding gunk from the panel lines using your airbrush at maximum rated pressure, at close range, shooting water or alcohol. Stubborn gunk may need a gentle prodding with a pick or sharpened cotton swab shaft.

I hope this helps a bit.

Kenny

[badlandsghost]

Good info on both, thanks.
I had thought about ca but was hesitant because a: never tried it before, and b: i did the lines w mechanics picks, so theyre wider than id like, and i was concerned about filling all that space.
Maybe the talc/ca method? Ive done that before for normal gap filling. I did pick up a set of the scribing tools lately which is what made me consider this in the first place.
Thanks
J

[Lt. Z0mBe]

Don’t use talc and CA in this application. It makes CA softer and that’s not what you want if you’re going to be scribing over it. Just apply the CA and let it dry. Good, old Loctite in the clearish, triangular bottle with the black ribbed cap like you get at WalMart is what you want here. It sands better than any of the hobby grades and doesn’t get harder than the styrene as it cures; most brands will get harder than the styrene or resin they’re applied too such that sanding them after 24 hours will mean your styrene sands away faster than the CA, making feathering difficult.

I hope this helps.

Kenny

[badlandsghost]

Thanks mate.
That sucks about the hardness. Hadnt factored that in, and have only done it in gen filling/smoothing stuff.
I hate that im so paranoid about trying to fix it, but it'd be the tie for the biggest scribing ive ever tried, with my first attempt being its co winner. Not to mention that the kits so pricey anymore.
Thanks
J

[jpolacchi]

I've used 5 minute steel epoxy instead of regular body fillers. Almost the same deal as using a super glue filler, but a "stronger bind" I.M.O and its not hard to scribe and it stakes tooling pretty well and just as easy to prime.

[Lt. Z0mBe]

I've used 5 minute steel epoxy instead of regular body fillers. Almost the same deal as using a super glue filler, but a "stronger bind" I.M.O and its not hard to scribe and it stakes tooling pretty well and just as easy to prime.

I used steel epoxy about 21-years ago on a scratchbuilt aerospace fighter to fill some intake divets in some kit parts. I was young and crazy, I know. The biggest problem was the hardness was far greater than the styrene, meaning I had to then add putty on top of the epoxy to get the line between epoxy and styrene to disappear.

I hope this helps.

Kenny

[jpolacchi]

I didn't have that problem using the 5 min. steel epoxy, but I wasn't using it to fill in large areas. The spots were relatively shallow and I started working on it right away after the 5 min. were up and the epoxy "set". It sanded smoothly, the scribing tool I made from K&S brass at the time had no issues carving panel lines. Typically I don't use epoxy unless I am working on a different kind of kit like a resin kit. Epoxy has a stronger mechanical bond than super glue. I'm not a big fan or user of super glue, but others have different experiences using it and opinions. Another way is to make your own filler. Grind up some Evergreen styrene rod, or cut up the unused sprues from your kit in small, small, small pieces, add MEK(all in a glass jar),let the solvent melt the styrene. Add more styrene if it is too runny, but its best to use a drop at a time and mix it until you make it the consistency you want. I'd "prime" the surface you are applying it to, but it should melt into the surfaces .It is a bit OCD and does take a bit of time to dry. You have to wait or hold the part(s) in place or back filling if you are filling in and joining more than one surface together. Mainly it won't "set/harden" until the solvent dries up and its solid, so maybe not always the best tactic to use? I've only done it a couple times to fill in very small gaps. You don't usually have that problem with Japanese kits.

[bigbluejavelin]

I am certainly no expert when it comes to scribing, but after I started reading this thread I watched a Youtube video about "sprue goo". I like the idea of it actually being styrene. Now I am no expert about anything at all, I am a "Jack of all trades, master of none" . I am currently experimenting with "sprue glue" for filling seams. Being a "Boomer Geezer" I have many kits and partial kits laying around. My first build was the custom show rod "the Red Baron" when I was in first grade (1969). The most important thing I have learned by partaking in this hobby has been patience. After watching the video that was made by someone way younger than myself (assumption based on his voice) I decided to follow his que and mix up a bottle to experiment (another thing I learned in my oh so many years in this hobby). Experimentation is the 2nd most important thing I learned as well as the virtue of never throwing away model parts . I plan on letting goo dry for at least 2-3 days before attempting to sand. Anyone else tried this?

[Rogviler]

I've had mixed success with sprue goo. If it dries then it's great, but if it doesn't then it seems to stay "rubbery" for quite some time. My advice is to use the hottest solvent you have so it evaporates quickly. Pure solvent is definitely better than, say, regular Testor's liquid cement. It helps to go in layers as well. Other than that, you can't beat the original plastic for filling imperfections in itself.

[jpolacchi]

I recommend MEK. It melts styrene like crazy,you barely need a drop to weld plastic parts together like styrene and ABS. You usually get a "good squeeze" that will come out of a seam when you press or are holding parts together with(after sanding) makes a seamless welded joint. MEK won't work on acrylic. You have to use acrylic solvent(for the same results).

[Lt. Z0mBe]

I don’t recommend the sprue goo for something you’re going to be scribing over. It dries way too soft, IF it dries at all. I’ve experimented with it for filling vehicle gaps as well as seams on figures; Shep Paine is where I learned that trick with figures. It’s not ideal for vehicle seams, because it outgasses much worse than Bondo or Squadron. Also, that process takes a loooong time. With putty, you leave a little raised, but feathered, fillet as you sand to account for this. With the sprue goo, you would have to leave an almost half-cylinder-shaped mound over the seam. Again, that assumes the stuff will dry at all. This says nothing of being unable to polish the stuff because, again, it dries too soft.

Also, your scribing pick or file or pin will not scratch, but just drag, through it, having an appearance like drawing a toothpick across cake icing. Remember, you’re talking about scribing, so the closer you can get to scratching and engraving and stiff straightness, the better. Trust me, if you’re going to be scribing over it, do not use sprue goo. All I use is MEK for a welding solvent, with Tamiya extra thin for delicate areas, and the MEK (Testor’s before) is what my sprue goo is made with. If you still need convincing, take a drop of sprue goo and place it on a piece of scrap styrene. Leave it and come back daily for a few days, noting how long until it is hard enough for your fingernail to not leave an indentation in it. If it’s less than a week, I would be shocked. Just use the Loctite CA in the triangular bottle with the black, ribbed cap for fixing failed scribe lines. It’s simple, dries quickly and feathers well.

I hope this helps.

Kenny

[jpolacchi]

You might be able to get the same result using acrylic. Its much harder than styrene and might tool better? You need to use acrylic solvent. I'd probably use the thick one that has acrylic in it and maybe some of the solvent to adjust consistency, but you still want to keep it "thick". MEK won't affect acrylic plastic at all. I think that might be an interesting experiment, but I prefer to stick with 5 min steel epoxy myself.

[starseeker]

CA is one of my go-to's. Use thick, don't use an accelerator, as that actually weakens the CS, and don't use talk or baking soda as a thickener/accelerator, as both, after about 20 years, start to dissolve. You have a couple of hours after the CA is dry to sand and scribe, otherwise, as others have said, it turns much harder than the styrene and makes sanding very difficult. My other go-to is .010 Plastruct rod or triangular rod, used with something hot, like Tamiya thin. I've never been good with stretching sprue, and the Plastruct is nice and hard, cheapish and plentiful, and it's easy to sand and match evenly with the surrounding areas and to rescribe, 1/72 scale, just use the end of a sewing pin as a scriber, the butt end stick into a pin vice or a piece of dowel. 1/72 scale, are you sure you want panel lines even to be visible?

[Lt. Z0mBe]

CA is one of my go-to's. Use thick, don't use an accelerator, as that actually weakens the CS, and don't use talk or baking soda as a thickener/accelerator, as both, after about 20 years, start to dissolve. You have a couple of hours after the CA is dry to sand and scribe, otherwise, as others have said, it turns much harder than the styrene and makes sanding very difficult. My other go-to is .010 Plastruct rod or triangular rod, used with something hot, like Tamiya thin. I've never been good with stretching sprue, and the Plastruct is nice and hard, cheapish and plentiful, and it's easy to sand and match evenly with the surrounding areas and to rescribe, 1/72 scale, just use the end of a sewing pin as a scriber, the butt end stick into a pin vice or a piece of dowel. 1/72 scale, are you sure you want panel lines even to be visible?

I agree about the accelerator. It makes CA too crumbly for scribing over. With regards to CA and baking soda, I have a scratchbuilt aerospace fighter with CA and baking soda filler I built in 1997. The CA and baking soda is just fine after 24 years. Also, nearly every model I have built since had some CA and baking soda on it as filler and all are fine. I always have placed the CA on and then sprinkled the baking soda onto the wet CA. But most people seem to add the baking soda first and then add the CA. Perhaps too much, “un-CA’d” baking soda is the culprit. This does not mean you want to scribe over CA and baking soda, though, as it’s more like trying to scribe over grout than plastic. Stick to straight CA for that. Good thing about the Loctite I reference above is it does not get too hard to feather into the styrene. Other brands absolutely get too hard after a day or two, but not the Loctite in the triangular, clearish bottle with the black ribbed cap.

I have to say this about panel lines. A scale of 1/72 is the same as the “real” thing seen from 40 feet away. Panel lines are certainly visible at that distance, so yeah he would want them to be visible. An experiment you can do is to take a photograph of a prototype vehicle with visible panel lines and hold it far enough from your face such that it’s the same size in your field of vision as the model would be when at viewing distance of say 10-inches. If you can make out the panel lines in the image, they should be that way on the model. You’ll find they’re visible down to at least 1/144 scale, BUT their intensity is not as great. I’ve done that many times as well as being in the presence of physical aircraft, pacing off to 40-feet (and greater) and seeing whether or not panel lines are visible. I found they’re visible out to 100-feet or more. Also, with the photograph method, you’re erring on the side of no panel lines, because some detail is lost due to the resolution of the photo; this further demonstrates the need for panel lines at a given scale.

I hope this helps.

Kenny

[Natsu-Rokka]

The best method I have found is using stretched sprue from the kit itself. Unlike sprue goo, it is not all soft, and using Tamiya Extra Thin or Gunze's Mr Cement S, it melts into the recesses and dries quickly for sanding, A good bond means you can scribe on top of it without any problems.

[seam-filler]

I have to say this about panel lines. A scale of 1/72 is the same as the “real” thing seen from 40 feet away. Panel lines are certainly visible at that distance, so yeah he would want them to be visible. An experiment you can do is to take a photograph of a prototype vehicle with visible panel lines and hold it far enough from your face such that it’s the same size in your field of vision as the model would be when at viewing distance of say 10-inches. If you can make out the panel lines in the image, they should be that way on the model. You’ll find they’re visible down to at least 1/144 scale, BUT their intensity is not as great. I’ve done that many times as well as being in the presence of physical aircraft, pacing off to 40-feet (and greater) and seeing whether or not panel lines are visible. I found they’re visible out to 100-feet or more. Also, with the photograph method, you’re erring on the side of no panel lines, because some detail is lost due to the resolution of the photo; this further demonstrates the need for panel lines at a given scale.

Agreed. Viewing a 1/72 model from 10 inches is the equivalent to viewing the full-sized vehicle from 60 feet.

[Lt. Z0mBe]

I have to say this about panel lines. A scale of 1/72 is the same as the “real” thing seen from 40 feet away. Panel lines are certainly visible at that distance, so yeah he would want them to be visible. An experiment you can do is to take a photograph of a prototype vehicle with visible panel lines and hold it far enough from your face such that it’s the same size in your field of vision as the model would be when at viewing distance of say 10-inches. If you can make out the panel lines in the image, they should be that way on the model. You’ll find they’re visible down to at least 1/144 scale, BUT their intensity is not as great. I’ve done that many times as well as being in the presence of physical aircraft, pacing off to 40-feet (and greater) and seeing whether or not panel lines are visible. I found they’re visible out to 100-feet or more. Also, with the photograph method, you’re erring on the side of no panel lines, because some detail is lost due to the resolution of the photo; this further demonstrates the need for panel lines at a given scale.

Agreed. Viewing a 1/72 model from 10 inches is the equivalent to viewing the full-sized vehicle from 60 feet.

Right, or 40 foot if viewed from five inches from your face, or 13 foot at 2.5 inches.

Kenny

[starseeker]

Just going through some of my old files on the computer, and re-discovered this one from a few years back:
https://www.youtube.com/watch?v=vRnKEws ... 7A&index=8

A great panel line primer from the great Paul Budzik. As he says, panel lines are completely subjective. Getting back to 1/72 scale, I'm of the barely visible if visible at all camp. Highlighted panel lines really only became common on models about 20 years ago. Now it seems nobody can build a model without pre-shading and then washes. There are so many Fine Scale Modeller tutorials on painting and weathering where I think the builder gets to a perfect model, then continues on for about two steps more and ends up with panel lines that would be about 4 inch wide bands on a real aircraft. Rather than adding interest or realism, I think that makes the model look toy-like, which ironically builders started adding panel lines to avoid their models looking like.

Everyone has different tastes, tho', and that's what makes life fun. But do check out the Budzik video(s). While I go and see if I can find those scribing tools he inspired me to make.

[southwestforests]

Highlighted panel lines really only became common on models about 20 years ago. Now it seems nobody can build a model without pre-shading and then washes. ... and ends up with panel lines that would be about 4 inch wide bands on a real aircraft.

And there's how model building is like psychiatry in having the scientifically unfounded fad of the current generation of practitioners.

(and here's where it is nice to be autistic and have your 'default setting' be to look at fads and go, "Huh? What? Why? I don't get it.")

[bigbluejavelin]

Starseeker, thanks for that link, it was a very well done video.

[starseeker]

Recently picked up a great scribing tool. Chose this site at random just for an example. This is the whole set but you can buy individually:
https://www.premiumhobbies.co.uk/scribe ... mplete-set
I've only got the black/narrow one right now. It's the best thing I've ever used for scribing straght lines. I also picked up Hasegawa's rivet tool and rivet guides. The flat edges of the thin stanless guides are great for guiding the scriber. A couple slow gentle strokes are all you need for a baely visible 1/72 line that won't quite fill with paint, and a few more strokes should be good for 1/48 and a couple more for probably in-scale 1/32. Their pointy needle looks interesting for curved outlines. Given the quality of the black, the needle tool probably works better than the old sewing pin an a pin vice. I might try it now, too...

[southwestforests]

Interesting data, will note it.