Portholes Help

Guido · Post by **Guido** » Wed Jul 18, 2007 6:06 am

Being in the midst of a freighter conversion I ran across this problem:
How to get very clean, even and evenly spaced line of portholes into scratch built surfaces (both straight and bent) The qualiyt of the final product is depending heavily on it: First trials show that the whole thing will look crappy, if even only one porthole is off.
How do you do it? Templates? If yes, what material do you use and how to place it onto the model so it stays in place while drilling or marking.

Cheers,
Guido

Rob · Post by **Rob** » Wed Jul 18, 2007 7:15 am

Masking tape.

Tape a piece of tape and smooth it don't onto a flat surface. Make sure the tape is wide enough to meet the top edge of the structure and cover the area of the portholes. Darw a line parallel to one dge of the tape and sufficient height below the deck edge. Mark in portholes.

Lift tape and then apply to model and press down flat so the top edge of the tape follow the deck.

Drill holes with a twist drill (best avoiding a power drill).

Hope this helps,

Cheers,

Rob

Guest · Post by **Guest** » Wed Jul 18, 2007 7:36 am

Good for startes no doubt!
Tried that first, but didn't get a straight line (maybe was too impatient, tough).
I hope somecome comes up with something different. Otherwise I'll go back to this method and train my patience!

Cheers,
Guido

PS.: What's on the bench, Rob?

Rob · Post by **Rob** » Wed Jul 18, 2007 7:50 am

Hi Guido,

Could be that either your drill was slipping or not centred.

What you could try then is pin-pricking the tape before going straight to the drill, that way you've got a guide hole.

On the bench is USS Guam, a modern amphib ship, albeit nearly finished.

Also part-way through rebuilding the USS Anchorage that I dropped and smashed a while back.

Guam should be done by the end of the week, Anchorage should take about another 3-4 weeks.

Cheers mate!

Rob

Ron Smith · Post by **Ron Smith** » Wed Jul 18, 2007 5:38 pm

Depends.......

If they follow the sheer of the hull I use a compass and trace the sheer at the level of the porthole centers. If they don;t follow the sheer I mark them like I do waterlines. To space them I set a compass to an accurately locatable part on the hull or deck edge and locate one porthole, then reset for each porthole along the line....te rick is to use the compass point to pinprick the first porthole location (will help center your drill) and then swing it in a small arc where the next porthole lies, reset and repeat.

Werner · Post by **Werner** » Wed Jul 18, 2007 9:08 pm

If you can, make a die which can be attached to the hull. Overhead projector transparencies can be printed from your computer and starter holes can be made with a knife. Further starters can be made from the Dremel or another drill and the satisfactory template glued to the hull with children's Elmer's.

Guido · Post by **Guido** » Thu Jul 19, 2007 2:06 am

Excellent input guys! Lots of good advice!

I'll try a bit this and that!
There is precious little space on 1/700 with the portholes only 2-3mm apart. It'll be tricky to "swing" the compass, but the means seem interesting for other 1/350 applications. Werners tip sounds great! Now, where did I put those overhead transparencies...

Guido

Foeth · Post by **Foeth** » Thu Jul 19, 2007 2:52 am

Be sure to pinpoint the location of the porthole with a centerpunch or something

If you don't, your drill will wander no mattter how accurate your position is. Using a compass is good, but using a ruler and a very shap pencil also works.I can draw lines within a few tenth's of a mm, so it works.

Oh, if you are drilling larger portholes, start with a smaller drill and finish with a reamer. Drills have a tendency to make triangular holes.

Guido · Post by **Guido** » Thu Jul 19, 2007 3:23 am

Good tip! I'll bear that in mind!

Guido

David Griffith · Post by **David Griffith** » Thu Jul 19, 2007 4:57 am

Dear Guido,

I follow much of the above advice.

A strip of masking tape to give a straight line. Mark very evenly with a sharp pencil and prick the centres with something sharp.

Even with this I find that a larger drill bit will tend to wander, so I drill a very small pilot hole (0.3mm) first, and then follow up with the the proper size drill (approx 0.6mm for 1/700). I use a pinchuck for extreme control and always use the same number of turns for each hole to get an even depth.

Finally, I turn the drill bit the wrong way round in the pinchuck so that the shank end is sticking out. I then push this into each hole so that any dust and swarf is hidden at the bottom of the hole. This gives a nice clean finish.

Kind regards,

David Griffith

Guest · Post by **Guest** » Thu Jul 19, 2007 6:41 am

Thank you all, Gentlemen!
This is a wealth of information and advice I would not have expected.
I am tending to take a good bit of advice from various replies and combine them.
I hope to be able to turn your good advice into knowledge tonight and let you know about my findings.

Guido

mike mccabe · Post by **mike mccabe** » Fri Jul 20, 2007 4:45 pm

An extension to this question, if a kit has portholes that are out of line or poorly done, what is the best filler to use to fill in the old ones and drill out new ones? I'm thinking it will need to be something pretty hard so as not to crumble if the drill needs to go into areas around the old holes.

Any suggestions?

Mike

Guido · Post by **Guido** » Sat Jul 21, 2007 11:39 pm

Hi, folks!
I tried your goods tips two nights ago and have a very satisfactory result.
I used tape with the positions marked with pencil. I pin-pricked the desired location and drilled .3mm first with .5mm following. Each porthole was finished after smoothing over using a reamer.
Thanks again foryour many tips, it looks very nice now!

Mike-
I use gel-type CA glue for resin. On plastic I back the old portholes with styrene and fill with humbrol putty. After smoothing over I apply thin CA glue. There are CA glues that comewith special brushes that are not effected by the glue.

Guido

Rob · Post by **Rob** » Mon Jul 23, 2007 3:01 am

mike mccabe wrote:An extension to this question, if a kit has portholes that are out of line or poorly done, what is the best filler to use to fill in the old ones and drill out new ones? I'm thinking it will need to be something pretty hard so as not to crumble if the drill needs to go into areas around the old holes.

Any suggestions?

Mike

I get on quite well with Squadron white putty. It really stinks and does need to be mised with a dash of liquid clue but it does the job very nicely on resin hulls.

Cheers,

Rob

Foeth · Post by **Foeth** » Mon Jul 23, 2007 3:12 am

An extension to this question, if a kit has portholes that are out of line or poorly done, what is the best filler to use to fill in the old ones and drill out new ones? I'm thinking it will need to be something pretty hard so as not to crumble if the drill needs to go into areas around the old holes.

Don't use putty. Buy some rod and glue some styrene in the bad porthole. This will prevent (to some degree) that your drill will wander to the weaker putty during drilling. Plastruct sells rod from 0.3mm and up in steps of 0.1mm (I say, buy the entire range while you are at it). Evergreen rod is an inferior product, I wouldn't use it.

BTW, if you don't want a see-through porthole, fill it up with rod, slightly recessed in the bulkhead.

Bob Payne · Post by **Bob Payne** » Wed Aug 08, 2007 3:31 pm

Where do you guys find a reamer small enough to do the portholes???

Guido · Post by **Guido** » Mon Aug 20, 2007 3:20 am

Hi, Bob!
Styrene is usually is so soft you can use a needle. The most important part is that your "mini-reamer" has a circular diametre.
Guido