Getting rid of joins/seams - gloop still visible

[RobL]

Hey all

 

This is more of a general modelling thing so I wasn't sure which sub-forum to put it in...

 

For a while now I've had some problems when it comes to dealing with seams/joins.  I tend to use "gloop", styrene sheet melted into Tamiya Extra Thin cement, to fill joins/seams.  However, no matter how much I sand and polish, and no matter how smooth it feels to the touch I can still see the seam/gloop when I put some paint down.

 

As an example I currently have a tank in progress that I have inserted pieces of styrene sheet to make it longer.  Either side of the these pieces I've filled the gap using aforementioned "gloop", and it's starting to get on my nerves because despite it feeling smooth after sanding I've still got a visible join area!

 

Anyone here any tips on how to avoid this happening or how to fix it so that I fill the seam and can't see the filler afterwards?

 

Thanks in advance.

Edited January 19, 2021 by RobL

[Bullbasket]

Any chance that you can post a photo of the seam that you are talking about?

 

John.

[RobL]

9 minutes ago, Bullbasket said:

Any chance that you can post a photo of the seam that you are talking about?

 

John.

 

 

Not very good one's, but here's a couple of 4 of the 8 similar joins I'm having a problem with.

 

 

Edited January 19, 2021 by RobL

[ckw]

That can be an issue, and I think there are two ways of dealing with it. First one is to make problem areas more visible. You can colour the filler and surrounding area with a sharpie marker. As you sand and low points will become very obvious and you can add a little filler (or sand a bit more) as required. The 2nd way (which could follow the first) is to use a primer coat. Some like Mr Surfacer, have different 'weights' and can work as micro fillers for small imperfections. The uniform coats also makes it easier to see imperfections.

 

Cheers

 

Colin

[RobL]

I just tried taking a Dremel to it with a grinding bit, on the slowest speed, and kind of smoothed out the "gloop".  Made a bit of a mess of the surrounding area though, so I think I'll try skimming it with Perfect Plastic Putty and see how that goes, see if I end up with a less visible result...

Edited January 19, 2021 by RobL

[Troy Smith]

1 hour ago, RobL said:

how to fix it so that I fill the seam and can't see the filler afterwards?

Try superglue/talc mixture.  dries really fast, and not as hard as plain superglue.   Also, really easy for fast touch up.   But, work it as soon as workable.   If you have not used it before, test on scrap, but i find it carves, scrapes and sands really well.    

I just use cheap poundshop SG  multipacks and talc, and mix it on old jar lids.  

 

sprue gloop needs time to dry and degas solvents,  in comparison the SG/Talc can be worked in a couple of minutes.   

This means the fill/sand/check/repeat cycle can be done in minutes, not hours or days.

 

Another possible for sprue gloop is brushing it flat with some TET. 

 

In the case of the pic above, try scraping the surface flat with a flat blade. 

 

Try to avoid a seam in the first place.  Not so easy in a modification like this, but often joins can be greatly reduced by dry fitting and adjusting before assembly.    Look at the work of @Ray_W  for examples of this. 

Initial care can saves a lot of messing about later.   I often see WIP models with seams smeared in putty and big sanding jobs and think how clumsy, messy and slow it is. 

 

 

As suggested by  @ckw  Mr Surfacer is very good.   It can be sanded, but also smoothed with solvents as well.

 

Also very good, but much slower is Milliput,  but this can be smoothed with water before setting,  and does not shrink, so much work can be done initially.   

 

HTH

PS

  

1 hour ago, RobL said:

This is more of a general modelling thing so I wasn't sure which sub-forum to put it in...

I would suggest in this section under modelling tips

https://www.britmodeller.com/forums/index.php?/forum/68-tools-amp-tips/

 

 

[Bullbasket]

You don't look as though you have much wiggle room there between the hubs, so I would say that Troy's suggestion of scraping with a blade to remove the excess. BTW. What is that that you are extending? Is it a WW1 tank?

 

John.

[Big Dave S]

2 minutes ago, Bullbasket said:

You don't look as though you have much wiggle room there between the hubs, so I would say that Troy's suggestion of scraping with a blade to remove the excess. BTW. What is that that you are extending? Is it a WW1 tank?

 

John.

I'd certainly agree with the craft knife option. The accessibility here looks difficult. It's a problem that sometimes crops up with aircraft and a curved blade can be used to scrape filler/seams off in instances like this.

[RobL]

3 hours ago, Bullbasket said:

You don't look as though you have much wiggle room there between the hubs, so I would say that Troy's suggestion of scraping with a blade to remove the excess. BTW. What is that that you are extending? Is it a WW1 tank?

 

John.

 

Yes, the room for manoeuvre is a bit tight.  The hubs can be replaced with some styrene rod though, I have plenty of it, if I end up sanding them off, a couple I think need replacing anyhow.

 

No, it's not a WW1 tank, it's a very old Games Workshop tank that I've been modifying.

 

Thanks though everyone, I'll bear the advice in mind.

 

What I did earlier with the Dremel+grinding bit plus a skim with Perfect Plastic Putty has at least eliminated the obvious "gloop" "strips".  It's looking a bit rough, but I can get away with that, or even sand it back I think if I need.  Doesn't have to look 100% perfect and smooth, just not an obvious join like it was looking...

Edited January 19, 2021 by RobL