1/72 revell U-boat U-96 [start 23.may.2011]

[maxfax]

Hello Marko,

Nice work. I've done lots of PE on aircraft and tanks, but these parts are usually added to the surface of the model, not replacing large sections. I have to say I am a little nervous about cutting out these sections from the model. I have no experience with epoxy cement- would any kind do? I have heard of "5 Minute Epoxy" here, so I will probably get some of that.

Rob

[Marko]

Hello Rob,

These PE sets are slightly thicker than the usual ones from eduard, Part, etc. (zoom, exterior...), especially the Winks and Dougies Ubrass flood gates set is thick. this means lots of bending control. Its not that hard actually, just align the pre-bent parts to the plastic, the instructions give you proper locations, mark the outside borders with a pencil, or very thin Pilot marker. Drill small holes near those edges (measure distance from edge till the flood holes with a caliper or ruler to achieve maximum seat ledge for the part in next step - usually 1 - 2mm), cut them out with the xacto knife, then use small ball milling bit to grind to the exact spot where all flood holes will be fully open, then make a seat for the PE part right up to the marked border (which was made at step 1), then thin the insides to get the thin hull effect, and last mount the PE using epoxy for strength, and CA for tacking them in on edges if necessary.

i used UHU's 5 minute 2 component epoxy, but any brand will do the job. You can also use 1 min, 10 min, 30 min, or 24h variants,... however 1 min is too short, since it will start to jelly up pretty soon, 5 is just about right, and i had still about 2 minutes to relax and place the parts in their place with no rush. final hardness will be achieved within 24 hours.

i used exactly this one:
http://www.uhu-profishop.de/images/product_images/popup_images/745_0.jpg

and here you can see the drilling procedure, as it was done on my 1/72 f-4 phantom (though here i didn't had to mark borders, since i made holes to existing airbrake housing covers


hope this helps,
regards,
Marko

[Anakin]

Nice job! Really looking with great interest your project. I like your posts with good pics and explaining every step.

-Anakin-

[Marko]

thanks for the compliments guys,
ill keep the updates coming always as soon as possible
i raided hardware stores again, bought new drill bits, to substitute the broken one, now i bought the budget version, so lets see how long will they last, since at the 3 pack boxing the difference was 2,5 euro. Next was the copper wire, diameter 1,5mm, ideal would be 1,2 but they didn't have one. Shortest length that i could buy was 1 meter, and the main cable is made from 3 wires,  so total length is 3 meters, which is more than enough. So i peeled the double insulation off, and cut the wires to 10 mm long bits, we need roughly 25 pieces per hull side.



now to the drilling holes for the GHG, and ill do them by hand, since these have to be accurate on spot.

Marko

[Anakin]

Because i

[Marko]

you are right, luckily i used 1,2mm drill bit, since it took only minor adjustment to fit in the bits. I measured it, and caliper says exactly 1,4mm diameter, but it does vary a bit. Now ill get back to the masking, since i want to apply putty only to the areas where needed

[Marko]

hello guys.

its not over yet, recently i have been doing messy jobs using putty, and i just did not make any pics of the process till now. Since my green stuff is running out, i ordered two tubes straight from UK on to the progress:

on the first picture you can see the difference between 1st of putty application, done my way. Firstly i masked of majority of the places where i didn't want to get the putty. This was been done in order to avoid unnecessary smearing all around, while filling the bigger holes. After sanding came one thin layer of primer. Upper hull half has second finer layer of putty sanded down (with exception of the anchor well, and a small portion at torpedo gates)




After all this chopping i felt confident enough to cut out the anchor well. Ive done this by drilling bunch of holes from inwards out with the smallest drilling bit i have (0,5mm) with slight negative angle out from 90

[maxfax]

Thats nice work that you are doing. I don't have the PE for the flood holes, but spent a great deal of time shaving down the plastic from the inside to open these holes. I made a decision to do little modification of the existing kit- I'm going to leave the anchor well and torpedo section alone and live with it, but I am always impressed when people go that extra mile.

Rob

[Marko]

Thank you max,

the build got now to a halt, since i have to wait for the mr surfacer liquid putty till 30. june. Im just unable to sand it smooth solely with the squadrons green, since PE has really sharp lines, and somehow gets often oversanded, or too thin and edges become visible after 1 day when handling again. And since i want it at least nearly perfect, not too thick layer of putty. So without surfacer im dead in the water.

So we are on hold for few days.
regards,
Marko

[Rokket]

Nice work!

I find the multi-strand electrical cable is excellent for really "hair thin" stuff, too. Like lamp cord, rip it apart, grab the very thinnest, hair-like single wire, and if you stretch it nice and taught and don't kink, it makes excellent railing cable. (as long as you affix it tight and no-kink, you wont get sag).

[Rokket]

Oh, putty - if you can find Tamiya grey putty - it's very creamy and vinyl-like, works wonderfully! BUT, 2 things: 1 - it can be "hot", as in solvent-like in too much and soften plastic; 2 - the second tube I bought I didn't use for a while and it's water and drizzly, and oozy and crap and I've thrown it out. I find Superglue (CA) is good for gap-filling, bt it is very hard and not so good for feathering.

[Marko]

Hi wink,

yea, those cables come in handy alots of times when building models. Though for the railings i got myself the ez line in various thicknesses and the lines from WEM the "lycra", though ill probably need alot of cables for the interiors, to boost up some extra details. And about the putty from tamiya, i held the darned thing in my hands at local IPMS contest 1 month ago, when one guy had his stand of tamiya and other products, considering either should i buy it exactly for this purpose or not... Yet again seems to me i got proven wrong, since i though to myself..aaah nothing can top the good old squadron

well, i've ordered the mr surfacer, which is use by a lot of modelers here, usually combined with squadrons green. (gosh im so mainstream)

the CA is fine too, though this one that i currently have, just doesn't cure that well without zip kicker, and if i use the accelerator, the glue tends to be much harder than the plastic, which causes again over sanding the surrounding areas..

well anyways, im a bit bored at the moment, so ill go try to do th ethings right with the squadrons again, i might get lucky

[Rokket]

Ahh, EZ Line! I bought a sample pack to play with looks like very cool stuff.

Yes, CA always gets very hard and that sand/blend is a problem.

good luck!

[Pat]

once that was done, i used 2mm ball milling bit to remove top of the plastic right near the drawn border, then some more filing came into action, and unfortunately i managed to stress fracture a bit of the hull in the process, marked with an arrow:


luckily for me fracture is minimal, and nothing what a drop of liquid cement could not handle..

i was aiming to thin the part so far as the PE part would fall in, with minimum requirements of filler when gluing the part in, i hope i achieved that

regards,
Marko

Sorry I didn't get to this sooner Marko, but a few personal problems in the last little while have taken me out of the loop.

Anyway, it's probably too late for this build, but in future a better and considerably faster way to cut out large sections of plastic is with a hot knife.  Using a Dremel with a milling ball is slow work, and if you touch the plastic for too long it starts to heat up and stick to the bit tip making you have to stop and clean your bit off.

A hot knife is basically an X-acto knife that heats up enough to cut through the plastic like a scalpel going through butter.

I bought mine from X-acto decades ago, and I don't think they sell them any more but you can easily make one.  It's just a soldering iron but instead of screwing in the soldering tip, you screw in the end of an X-acto knife with a # 10 or # 11 blade in it.  The threads are the same.  I've used mine as a hot knife for so long that I've lost the soldering tip and only use it for cutting. 

Over the years, I also found that I wanted a switch, so I put in one of those inline gear switches, and painted it red when it was 'on' so I knew which way the switch was set.

[Rokket]

You've mentioned the Hot Knife before, I have to keep reminding myself to give it a try. I'm sure I've seen one somewhere, ENCO maybe? MicroMark?