discussion Removing mold lines from small parts like bombs

[Guest]

I'm looking for ideas on the best way to remove the molding and assembly lines on very small parts, like bombs, rockets, and fuel tanks.

No matter how much sanding I do, the lines still show up when I paint the parts, and I am afraid to sand much more as it will remove surrounding detail.

Any suggestions?

 

[Swagman 070]

Scrape gently with a scalpel to get the worst of the mold line off. Then sand using wet 800 grit and then wet 1000 grit, wet and dry paper. I glue strips of the wet and dry to the sharp edges of makeup sponges for precision work (between detail lines and awkward corners).

Steve

 

[Ian M]

More of an observation than help, but if you have problems in "loosing" joint lines, they keep showing as a fine line, it's a sign of one of two things, or both.

Either you have not used enough glue or not allowed enough time for it to dry 100%. Or both!

If there is an ooze, all the better as it just gives you more to play with before you hit the parts you are glueing together.

(If this does not make sense it is due to not enough tea in my rum!!!)

Ian M

 

[stona]

Mold lines should sand off and not leave a "ghost". If they do it's due to a manufacturing fault (it does happen) and you'll have to use some kind of putty or surfacer ,followed by more sanding,to get rid of them.

Assembly lines,seams,are a whole other thing. Plastic cements "weld" parts together chemically by dissolving the plastic of the mating surfaces with a solvent. The first thing is to make sure that the mating surfaces are infact mating. Warping,bad molding or something as simple as a badly molded locating pin can sometimes prevent this.

Everyone uses different glues but once you are happy that the two surfaces to be joined mate perfectly you should apply the glue and tape or clamp the parts together. Hopefully you should get an ooze of "molten" plastic from the seam. Leave it alone until dry. When you scrape this dried plastic off,the seam behind it should be filled (with plastic) and not need any further filling.

Someone did a very good article on seams on another site and if I can find it I'll add a link to this post.

Cheers

Steve

That was easy! Everyone should read this,however experienced. Gerald Voight has produced a superb tutorial in this thread.

http://www.aeroscale.co.uk/modules.php?op=modload&name=SquawkBox&file=index&req=viewtopic&topic_id=111677&page=1

Steve

 

[Ian M]

That is a most interesting read Thanks Steve.

See its like I said, more glue and let it dry propper!

Ian M

 

[Guest]

And there I was restricting putting to much glue on.

A very constructive piece about glueing & filling especially for me as a starter.

Matter of interest on another forum a chap from the USA was berating the British fill it attitude. He said that you should shave & fit. Seemed to indicate that he did not use filler.

Seemed to me that in some cases that may be true. But also appears that a good number of times if you shave here it creates a gap there.

Laurie

 

[stona]

And there I was restricting putting to much glue on.Matter of interest on another forum a chap from the USA was berating the British fill it attitude. He said that you should shave & fit. Seemed to indicate that he did not use filler.

Laurie

It's a combination of the two. If you get the surfaces to mate perfectly and glue them properly you can get away without filling nine times out of ten. There are always going to be occasions when there will be gaps that need to be filled. I used no filler at all on my current Bf109 build,the fit of the Hasegawa kit is so good that with a couple of minor adjustments it simply wasn't required. I can't say the same for the Zoukei-Mura Ta152 I did previously!

Cheers

Steve