Joint flaws

[Stressy]

How do you do it? I'm not really asking about filler itself, but rather what is best to use to reveal any flaws in the joint or filling - I  hate visible joint lines. I use either Tamiya or Halfords grey primer but its very easy to end up with an over thick layer of paint before you even start painting proper, and panel lines and other details to re-scribe even after you've given the primer a light sanding back. Do any of you have  a killer alternative approach? 

[Ade H]

@Stressy Use the best possible tools, have a properly defined preparatory process, and look very carefully in bright multi-directional light.

 

I don't mean that to seem critical, but that is the essence of it. It's not complex, but there is no shortcut which avoids having to put in the time and discipline, doing the same thing with the same care on every part. Even if there are 800 of them... 😫 And then doing it all over again next week/month until you get better at it. Call it paying homage to the gods of modelling because none of what we do ever goes right first time!

 

Priming need not be seen as a remedial step; it's more about unifying surfaces. I only prime when I actually need to, not because someone said that we must. I now rarely find that priming reveals flaws because I make very sure that all errors are gone before that. White plastic is probably the hardest to deal with, but not impossible.

 

As for filler, that's a hard one. (Pun intended.) Is what you use now not working for you? Are you using it correctly? Are you using the wrong product for the job? Maybe you need to gather a bunch of products and test each one thoroughly. I see some modellers criticise good products without qualifying their complaint, so I never know the context behind it. So I sit here thinking that it works for me, but obviously I don't want to say that to them. My advice to you is what I tell myself to do when I'm stuck: practice and experiment.

Edited September 1, 2021 by Ade H
added tag

[pigsty]

I agree with Ade H about the light.  If you suspect there's a flaw, raking light is brilliant for showing it up.  And if that fails, there's touch.  Your fingertips (and your tongue, incidentally) are remarkably sensitive - with your eyes shut a human hair can feel as big as a pencil.  If the space is too tight, there's your nails; and if that won't fit, I use a pin.  Just hold it gently and draw it across the joint and you'll feel any ridge, gap or step very easily.

[Ade H]

That's good advice about feel. I've used a seam scraper to feel steps because it's kind of like a tuning fork effect.

 

Also, I forgot to mention that exactly how you smooth filler/putty is crucial. That may seem obvious, but different types respond well (or not) to different techniques, tools, and sanding materials. Again, it's useful to experiment.

Edited August 31, 2021 by Ade H
added info

[Procopius]

15 minutes ago, pigsty said:

 Your fingertips (and your tongue, incidentally) are remarkably sensitive 

 

This raises troubling questions.

[Bertie McBoatface]

4 minutes ago, Procopius said:

This raises troubling questions.

 

Ah come on, we all lick our models when nobody's looking. 

 

Don't we?

 

Just me then...

[Stressy]

Thanks,  I  think I do most of that - not the licking! I  probably need to do more of the looking before I  resort to primer. Just checking there wasn't a miracle cure that's passed me by I guess.

[ckw]

OK here is my miracle cure - a tip I picked up on BM, but unfortunately I can't remember from whom ... anyway, who ever you are, thanks.

 

Run a black sharpie over all joints or other filling after I think I've sanded to perfection. Then lightly sand off the sharpie ink. Any areas that need further work will become very obvious.  Usually I apply the Sharpie before what would be the final polish sanding.

 

Cheers

 

Colin

[Heather Kay]

2 minutes ago, ckw said:

Run a black sharpie over all joints

Please bear in mind that unless you manage to remove ALL traces of the Sharpie, marks will bleed through any primer and paint layers. Better to use a dry marker intended for whiteboards.

[bentwaters81tfw]

Similar to bodyshops. Prime, then a black mist coat and rub down. Shows flaws and pinholes.

[ckw]

1 hour ago, Heather Kay said:

Please bear in mind that unless you manage to remove ALL traces of the Sharpie, marks will bleed through any primer and paint layers

Very good point Heather - I should have mentioned that. As I always give the model a wipe with IPA or Mr Hobby Levelling Thinner before priming/painting (which removes Sharpie) this hasn't been an issue. But marker ink does have remarkable powers of coming to the surface - as anyone who has tried to paint over a child's marker scribbles on a wall will know! (Tip: seal the scribbles with clear nail varnish first).

 

Cheers

 

Colin

[Stressy]

Thanks - marker ink is a lot thinner than primer and might be just the thing I was after.

[McG]

I've seen people using Tamiya Panel Line Wash to check panel lines etc before priming - both for ones that have been filled and for others that need to be rescribed. 

[Stressy]

Not heard of that product? 

[McG]

It's a really thin enamel based pin wash that uses capillary action to fill panel lines. 

 

https://www.tamiya.com/english/products/87131_133panel_accent/index.htm

 

It's not officially imported by the UK distributor for Tamiya. You can however get it from Amazon, eBay and other suppliers who are EU, US or Far East based. 

 

This is an example of where it is being used to check the filling and scribing work prior to paint. 

https://www.britmodeller.com/forums/index.php?/topic/235084404-132-brit-phantom-fg1-xv571-conversion-from-tamiya-and-wild-hare-set/&do=findComment&comment=4182581

[dnl42]

As suggested above, good joint preparation goes a long way eliminating seams.

 

For larger gaps, I fill with plastic strip.

 

My favorite method for very thin seams is medium CA. Apply CA to the joint with a pin or applicator. After about 20 to 30 minutes, file smooth with 4-cut and 6-cut files and then polish with abrasive pads . DO NOT let it cure overnight before you file the joint lest you embed a very hard rock in your model. The CA-filled seam will likely be visible, but raking light should show it a continuous shine over the joint. Any shine discontinuity needs additional treatment.

 

This shows both plastic-filled (red circle) and CA-filled (green circle) seams; the right side shows a continuous shine over the CA.

 

HTH

-- 

dnl

[Sharknose]

Dnl42,

 

Without wanting to derail the thread, if I could ask, and I'm still learning, why and what do you use on those black access panels, and what's the white piping on the main part joint at the top. 

 

I've not seen this done and do struggle with these joints often. 

 

Thanks in advance.

[dnl42]

@Sharknose, take a look at this post.

 

HTH

-- 

dnl

[Sharknose]

7 minutes ago, dnl42 said:

@Sharknose, take a look at this post.

 

HTH

-- 

dnl

Cheers mate. I see it's a raised seam then. I thought it was a method of getting rid of seams, all magic and wizardry. Thanks for your reply.

[Ray_W]

If I have an area where there is a critical seam I airbrush silver lacquer - currently using Mr Color (8) Silver thinned with Mr Color Leveling Thinner. Lays down thin, drys quickly and defects are easily seen. I just spray the offending area.  There is no loss of detail attributable to the paint. Sands well and has no impact on following paint coats.

 

I am aware of the sharpie solution although the above works very well for me. Spencer Pollard also describes another method that may be of interest here:

 

https://www.youtube.com/watch?v=i73nVXG8e9c

 

I have been tempted to try the method he describes for sink marks.

 

Ray

 

[MikeC]

I paint the seam with unthinned Tamiya acrylic in a colour that contrasts with the plastic, then sand it back.  It's a great tell-tale, the paint is thick enough to fill any minor imperfections on its own, and as I use Tamiya and Mr Hobby acrylics is perfectly compatible with paint (unlike the sharpie mentioned above).

[spruecutter96]

On 8/31/2021 at 9:18 PM, Procopius said:

This raises troubling questions.

Surely, this is a case of "suck-it-and-see"?

 

I shall acquire my outdoor garments forthwith....

 

Chris.