Removing Seams - Is there some magic method?

[nheather]

Hi,

 

Talking about the seams on plastic parts where the two halves of the mould meets.

 

Is there a cleaver way of removing them - I just scrape with a edge of blade and/or sand.

 

That works on small parts but on big chunky parts I find it quite dissatisfying that I can't just take the seam off without bits the plastic either side with the blade or the sander.

 

Is there some magic method.

 

Also bonus question:

 

When the seam runs long a moulded spring - what do you use to remove the unwanted material (web) between the spring coils?

 

Cheers,

 

Nigel

[Nigel Heath]

Quote

When the seam runs long a moulded spring - what do you use to remove the unwanted material (web) between the spring coils?

 

I would probably use a small triangular file or scratch build the thing using wire to replicate the spring.

 

 

 

 

[Graham Boak]

If the two parts meet perfectly but there is still some visible seam, try filling it before sanding.  If the seam is visible because one side is higher than the other, then you cannot get away without working at it, although you can use filler on the low side to reduce the damage done.

 

A small piece of emery paper/wet-and-dry may get into the web of springs and similar pieces, but I'd try a very sharp knife first.

 

If anyone does know a spell that solves these problems, they are keeping it to themselves.

[bzn20]

6 minutes ago, Nigel Heath said:

I would

 

6 minutes ago, Nigel Heath said:

replicate

You and your avatar.. Its will and exterminate ,then repeat a couple of times!

[Beardie]

Seams are a swine to get rid of. Even if there doesn't look to be a seam there on the bare model, once you get the paint on, hey presto! the seam becomes visible again.

My favoured technique, admittedly on very well engineered and close fitting Wingnut Wings kits where gap filling isn't usually required and the heights of the two halves line up well, is to paint the two fuselage halves the appropriate colour (I use enamels but, if you use acrylics I am guessing the same will work with primer) and, once the halves are joined, I will use P1500 wet and dry paper with plenty of water to attempt to remove the seam. If it is still visible once the plastic along the seam starts to show through the paint I give it another reasonably heavy coat of paint (I use the airbrush but a spray can or brush should do the same job) just along the area of the seam and, once the paint has dried well enough, repeat until the seam becomes invisible.

 

If there is a disparity in height of the sides or other imperfections, flash etc. I start with diamond files to roughly level things off followed by wet and dry paper smooth the surface then spray and cut back as I described above until the seam vanishes.

[Bullbasket]

If I have a seam to fill where the two halves are equal in height, but you have a very small trench between them, I paint correction fluid along the seam and once hardened, rub it down with very fine wet and dry.

 

John.

[CurrantBunbury]

2 hours ago, Bullbasket said:

If I have a seam to fill where the two halves are equal in height, but you have a very small trench between them, I paint correction fluid along the seam and once hardened, rub it down with very fine wet and dry.

 

Now that's one I haven't heard before. I think I'll try it next time I've got a gap that size.

[Bullbasket]

1 hour ago, CurrantBunbury said:

Now that's one I haven't heard before. I think I'll try it next time I've got a gap that size.

It works well, but it won't take hard, coarse sanding, so therefore, just use fine wet and dry.

 

John.

[Mike]

You could of course try these.  I wish I remembered them more often than I do, TBH

[Gorby]

9 minutes ago, Mike said:

You could of course try these.  I wish I remembered them more often than I do, TBH

That's an interesting product - I hate sanding. You mention that it is good for resin, would it make plastic melt?

[Aeronut]

For mould seams on individual parts I use a selection tools ranging from the scalpel blade used for paring / scraping, needle files, nail buffing sticks (cheepo triple grade ones suffice), emery paper and even a brass wire brush intended for cleaning suede shoes. The last is used on those pesky spring mouldings.

[Mike]

35 minutes ago, Gorby said:

That's an interesting product - I hate sanding. You mention that it is good for resin, would it make plastic melt?

 

Not if you use it as directed and allow it to skip over the plastic.  I've used it in the past to sort out the seams of 1:35 styrene figures before now with no melting problems.  If you press too hard though, you'll really wish you hadn't

[Jon Kunac-Tabinor]

Personally I'd say that a sharp, new scalpel blade, followed by a sanding stick does the job for me. A good set of fine-pointed and circular Swiss files are also a decent weapon for seam removal too - you can often get the point into crevices and remove the seam line like that. Sometimes though if one also has some mould misalignment - then removing the seam can result in losing too much plastic - so it may be case of levelling up the area with filler before truing it up with sanding sticks etc ( I'll just say Fonderie Miniatures, and leave it at that!)

 

I have pretty much totally switched to CA and talc as my filler of choice nowadays - it can be mixed to different viscosities, dries fast and hard, and will sand out and feather beautifully.

 

Cheers

 

Jonners

[Kuro Nezumi]

You could try the Citadel Mouldline Remover. A bit pricey but it works wonders for the light removal of plastic.

[Mike]

There's also this 'un wot I dun reviewed once upon a time.  That's mainly for curves & tubes

[nheather]

The Hobby Elements burrs look interesting but are they still going.

 

Can't seem to find their products online and their last facebook page was over a year ago.

 

Cheers,

 

Nigel

 

 

[CedB]

I'll second the molding flash sanders and the Citadel Mouldline remover - when you get used to them both tools seem to 'know' what's flash and remove it without scratching the plastic.

Hobby Elements is a one-man band and I last emailed him (hobbyelements_info@yahoo.com) last June... worth a try though.

[Ade H]

I use Alec seam scrapers (from Models R Go). Alec tools are not cheap, but I swear by them.

[Beardie]

Scrapers are very handy. Cabinet makers have been using them for centuries.

 

Garlick do a good choice at reasonable prices:

 

http://www.flinn-garlick-saws.co.uk/acatalog/CABINET-SCRAPERS.html

[spaddad]

very useful post Marty, thanks.