Removing seams off funnels?

Jim R

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Hi Bob
Lots of interesting ideas and approaches to the issue. When a part is removed from the sprue, by whatever method you use, the plastic around the attachment point often gets stressed. You can sand back the attachment point nib left until it is perfectly smooth but the stressed area may still show. That is one reason why I use a primer coat - it show whether the area is ready for paint or needs further sanding or filling. As Tim says ....
I’d say the sprue scars only need to be removed if they show under the paint.
Jim
 

zuludog

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I don't make ships so I have never needed to sand a funnel.
But I do make planes, and sand things like bombs and rockets

Usually when you sand the joint or moulding marks of those you obtain a good circular cross section, which would be a circular or a sort of oval section for a funnel You might need a bit of filler or Mr Surfacer to fill any small gaps but it should still line up OK
However, sometimes the two halves of a bomb are offset so the only way to obtain a smooth joint line would be to sand off so much plastic that you end up with a flat surface instead of a continuation of the round one

In this case I would roughly sand the joint and any flash, then fill the line & gap with filler or a piece of stretched sprue & filler, which would require more sanding & shaping to restore the cross section of the funnel, bomb, or whatever
So if your funnel is bad, try that, and check with a coat of primer before while you still have decent access, before complete assembly
 

BattleshipBob

Bob, bob, bobing along!
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Bob
Hi Bob
Lots of interesting ideas and approaches to the issue. When a part is removed from the sprue, by whatever method you use, the plastic around the attachment point often gets stressed. You can sand back the attachment point nib left until it is perfectly smooth but the stressed area may still show. That is one reason why I use a primer coat - it show whether the area is ready for paint or needs further sanding or filling. As Tim says ....

Jim
Thanks Jim, will so soon after primer!
Hi Bob

The IPMS Seam scraper (#1) ( Products – Seam Tools – IPMS (UK) (ipmsuk.org) ) is a good investment for scraping seams on curved surfaces

View attachment 433272
Thats interesting!
I don't make ships so I have never needed to sand a funnel.
But I do make planes, and sand things like bombs and rockets

Usually when you sand the joint or moulding marks of those you obtain a good circular cross section, which would be a circular or a sort of oval section for a funnel You might need a bit of filler or Mr Surfacer to fill any small gaps but it should still line up OK
However, sometimes the two halves of a bomb are offset so the only way to obtain a smooth joint line would be to sand off so much plastic that you end up with a flat surface instead of a continuation of the round one

In this case I would roughly sand the joint and any flash, then fill the line & gap with filler or a piece of stretched sprue & filler, which would require more sanding & shaping to restore the cross section of the funnel, bomb, or whatever
So if your funnel is bad, try that, and check with a coat of primer before while you still have decent access, before complete assembly
Many thanks for the advice, appreciated

Bob
 

Airborne01

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Steve
Hi Bob
Lots of interesting ideas and approaches to the issue. When a part is removed from the sprue, by whatever method you use, the plastic around the attachment point often gets stressed. You can sand back the attachment point nib left until it is perfectly smooth but the stressed area may still show. That is one reason why I use a primer coat - it show whether the area is ready for paint or needs further sanding or filling. As Tim says ....

Jim
I concur Commander!!
 
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