seams

[tucking fypo]

There are a couple types of seam that are kind of kicking my ass. One of them is the kind where the two mating surfaces don't meet at the same angle like they should.

Take this, for example:

The seam is extremely thin and minuscule but is enough to show through paint and primer.

I applied some liquid cement to the surface to highlight the seam. The graphics help too.

As an aside, the blue thumbs-up is the area that's always given me issues for the past several years. I got it smooth and uniform.

 

[Junkie]

You're dealing with 2 beasts. A seam on a flat surface and a seam on a round surface.

For the flat one use some putty and apply a thin coat, covering the seam. Once dry sand it down, feathering the edge. Don't sand it back to the point where so see the seam again.

Round surfaces are tough, cuz you don't want to flatten one side of it. Again a thin layer of putty can work. To sand it, try taking a piece of sandpaper, cut a longish thin strip. Secure the model somehow (with your knees - i've done it that way b4) and then one end of sandpaper strip in one hand, other end in the other hand. This will allow you to sand around the cylinder. Allow the strip of sandpaper to wrap around the piece, maintaining the roundness. Go slow, check often. Don't sand too much - just slow right down, force patience.

I'm sure there are other techniques that will be shared here too.

 

[Grendels]

I went through much the same thing with one model I have been working on. The 747 space shuttle model. It had a rounded seam that was uneven between the two sides.

I would take the advice that Scott gave you. The only thing I would add is to use wet/dry sand paper and sand with it wet. Start with 600 grit and go from there. You can't remove much material with that grit, so it forces you to go slow. The water helps to keep the paper from getting clogged up with the dust that sanding forms.

 

[Junkie]

Nice tool Jingles - must be a quick DIY solution too.

Good call on the wet sandpaper.

 

[tucking fypo]

Secure the model somehow (with your knees - i've done it that way b4) and then one end of sandpaper strip in one hand, other end in the other hand. This will allow you to sand around the cylinder. Allow the strip of sandpaper to wrap around the piece, maintaining the roundness.

Like a shoe shiner?

[quote author=Scott Girvan]Go slow, check often. Don't sand too much - just slow right down, force patience.

Always good advise! Thanks! ;D

 

[Junkie]

Shoeshiner, yes - that's a good comparison really.

It's really easy to overdue it and flatten a site. Slow and patient, checking often - that's the skill to be learned here.

 

[tucking fypo]

not really certain why the super glue and baking soda didn't work. I thought that it would be thin enough to get into that seam - any seam really and fill it.

 

[Exarkun77]

I'd just like to add one thing: don't hesitate on making multiple layers of paint, and sanding down between each layer of silver/primer. I suggest silver to help you notice bumps and holes, then primer when the hull is smooth.
you might try something like putty, sand, silver, sand, putty, sand, primer, etc.
Long process, but works fine.

 

[Just Mike]

so I understand correctly, sand away the silver, yes?

 

[Grendels]

Yes, but examine the results after you paint on the silver. It will let you see imperfections in the seam. Also, if you sand lightly, it there will be silver paint left where there are low spots and when you first start to sand, the silver paint leaves the high spots first.

 

[Just Mike]

okay, just wanted to make double sure. I admit to being a little dense in these matters and I'm not ashamed to say I was a little fuzzy on the issue - whether the silver paint applied was supposed to reveal seam lines or if you had to sand it off first and how to know when you've sanded enough so as to not take away any more putty. I guess once the silver is gone, stop, right?

 

[Grendels]

I use a pretty fine grit of sand paper when working seams. 600 grit wet/dry paper. And I sand it wet. Just one or two passes will show high spots, a bit more time with it, will show low spots. Experiment a bit, to get a feel for it.

I usually stop before all of the silver paint is gone. This method is not fool proof by any means, but it is better than just using your fingers to feel the seam. It can feel really smooth, and still have rough spots that show under paint.

 

[Just Mike]

Question: will non-MEK cements dissolve ABS the way styrene melts with "hot" glues? Maybe if I figured out a way to glue the seam on the war machine a little better, I may not be having this seam issue.

It is getting better and better though. Y'know, thanks to everyone's help!

 

[Just Mike]

is it possible to just see the seam under the primer without being a depression there? There's a sizable one after I primed but I can't feel it and there doesn't seem to be a shadow cast in the light.

 

[RocketSilo]

I use the proweld when I can, than try to get the raised bit of ooze from the seam. I still end up with a little filling and sanding

one thing that helped me on my last build was applying some tape a little off each side of the seam, before filling and sanding..I tend to go overboard with the sanding part . once the seam was filled/sanded I removed the tape and lightly feathered it in.

 

[Just Mike]

yes, that's been covered and I have started using that practice. Working really well, too.

This is on a kit that I did prior to learning that technique and has multiple layers of putty and primer on it.

There's a seam that I can see but not feel and it doesn't appear to be depressed. Just wondering if it's something I should fix or go ahead and paint.

 

[RocketSilo]

try going over it with a polishing stick ,, that will reveal any flaws pretty well ,,
something else I picked up on my last build.

I learned it from a youtube vid..and it really has made my seams better..not perfect yet ,, but much better
I'm still in novice mode.and perfect seams are still elusive to me.