conning tower floor

[u-kater]

Hi all,

Does anybody have an idea to create a conningtower floor for a type IX early war other than photoetching? I have a problem creating the even little squares on the "wintergarten" aft part. Any suggestions?

Kind regards
Wiljan Bakers

[safrole]

You should reconsider photoetching, only

You should reconsider photoetching, only skip the "photo" part. Take a thin sheet of brass and cover it with masking tape completely, front and back, making sure the seams between tape pieces fall on the lines between your grid plates, etc. Then use the razor knife to cut out your squares.

Get PC board etchant solution from electronics store (brown liquid ferric chloride), enough to fill up a glass container so you can hang your brass inside, using tape as a hanger. Brass that is .25mm thick can take about an hour and a half to burn through. Some people use tape at the edges of the piece to make a "boat" so that the etched part faces down. This "boat" is gently set on top the solution, like leaf on the water. This lets the etched salts fall away from the brass and uses only a thin pan of solution.

If you want to get fancy (who doesn't?) then after 45 minutes you pull the piece out, wash it off, and cut detail lines into the tape and peel them out. Then you can continue and get nice etched lines between your "grid plates".

I know it sounds like a lot of work, but the average person really can achieve superior results. The thinner the brass you use, the faster and more clean will be your final piece.

[bob the builder]

My brother-in-law has a sign

My brother-in-law has a sign making plotter. I wonder if the vinyl that he uses for that could be cut on the CNC and then applied to the brass?

I could do up the program in CorelDraw and get CNC cut grids and gratings on thin brass. Even complete decks could be done pretty easily. I should try this for my 1/72 Nautilus that has such lousy and warped detail on the upper deck...

Any reason that this wouldn't work?

[safrole]

Hah, funny you should mention

Hah, funny you should mention that...

Yes, signmaking vinyl works great! I have been in the business about 7yrs now. I thought I was a genius, applying my graphics business to photoetch and dispensing with all the "photo" hassle of it. But the sheer tedium of weeding (picking out) all those little pieces means it's only easier if you're making one or two for yourself. So I trashed the idea, but it's quite feasible for the do-it-yourselfer.

You know, as the brass etches, it etches in all directions at once. The process of etching "sideways" underneath the resist or vinyl is called undercutting. Thin material undercuts very little. Thicker will undercut much more, which requires that you put identical art on both sides so the holes will meet in the middle. For that, getting near perfect alignment is a must, and is a real hassle with computer cut vinyl. Plus you don't know if it's wrong until you ruin the brass and waste your time. But for thin material, it sounds like you could do a million little one-time projects.

When you set up your file, plan on the acid eating up 20% extra of the material thickness. If your relative's plotter has a swivel knife that casters behind the carriage (most do) then the square corners where the knife turns may have little boogers that can make trouble. There is a setting on the plotters to correct this called "corner sharpness".

Also I have an idea for ladders on a nautilus type boat. You would etch thicker brass into a ladder shape, purposefully too fat, then peel off the vinyl and dunk it in the acid for a while more. That will round off the lines and you can bend the four ends 90 degrees, all the same direction. It would make a standoff ladder that had a very delicate rounded look and no solder to clean up at every joint. Just an idea.

[safrole]

Many moons ago, over a

Many moons ago, over a half-built Robbe...

[u-kater]

YESSS!!!!!! IT WORKS AGAIN!!!!!

I was

YESSS!!!!!! IT WORKS AGAIN!!!!!

I was not able to send reply on postings on this topic due to some difficulties with my status as member.

But now it works again.

Thank you Safrole for your tip. After I red it I went to"bisuness" immediately. IT WORKED PERFECTLY!!!. After making the floor I could finish the CT of U-123 in a days work. I didn't have the problem on the floor of the CT of U-805 because it was made different(late war). Hope you were not offended me not answering your posting. Your tip did the trick and is usefull for other projects to come( deckhatches, railings outlets a.s.f.) like the decks I have to scratchbuild.
Thanks again.

U-Kater

[safrole]

Great, I'm glad it worked

Great, I'm glad it worked for you. Thanks for the positive feedback.