Scratch-built 1/96 Oscar II

[gerwalk]

Thanks a lot Kevin! That's

[color=#000000]Thanks a lot Kevin! That's the clearest color pic of that section I've ever seen. Looking back to the Kursk in dry dock they seemed to be painted the same way (BTW]http://www.subcommittee.com/forum/icon_smile.gif[/img] These forums sometimes are weird...)

As for the crests]

[gerwalk]

OK, here is a good

OK, here is a good scan (1200 dpi) I did of Zvedzda's 1/350 Kursk crests]http://img.photobucket.com/albums/v393/Gerwalker/Kursk/kurskcrest.jpg[/img]

The white crest seems to be the one on the right



Edited By Gerwalk on 1130802139

[KevinMC]

Pablo- Thank you for posting

Pablo- Thank you for posting those. From the pictures I've seen of the Kursk, I'd only ever noticed white on the side emblem, but all the shots I have are at a bad angle and significant distance.

Myles- Here's a couple of shots of my tools, and the materials I'll be using for this build. Nothing fancy here.

[KevinMC]

And here's the plug covered

And here's the plug covered in drywall compound. (Further sanding still required...) Because of the stiffness that it adds to the foam, even for areas that don't need any building up have been hit with a skim-coat of compound. Definitely the hard part of this is getting that nose evenly shaped.



Notice that I've attached the tail "cones" at this point, and that the very end of them has a metallic look. I didn't expect the foam and d/w compound to hold shape as precisely as I'd like at the prop/hull interface, so cut the aft end of the hull 0.5" short and glued a pair of cylindrical shaped aluminum peices onto the ends to hold a perfectly round shape. These have now been blended in under the drywall compound so that only the end is still visible.

[gerwalk]

You're welcome. Keep posting the

You're welcome. Keep posting the construction process, these are the kind of things that make these forums unique!

[steveuk]

Kevin, really enjoying all these

Kevin, really enjoying all these progress pics. Even pics of tools used. Looks like a plasterers plastic float you are using as a sanding block - neat idea!
First time I have seen this 'spineboard' and interlocking slits method. Sure is better than the rod through the middle method.

You never know who's learning what. But "a picture is worth a thousand words".

[mylo]

Kevin,

Thanks a lot for

Kevin,

Thanks a lot for the tool shots. I like it when a project doesn't need anything fancy ( = expensive).

Do you find that you have to be careful with how much pressure you are applying when sanding the DW compound in order that it doesn't crack on you ? ....or is the stuff pretty tough when on the foam ?

That long looking "thing" (that looks like sand paper strip) looks a lot like a sanding pad for a long board for automotive body work. A long board is a tool that auto body guys use to do some final prep on body panels that contain body filler (bondo) before prime / paint. Is that what that is ?

Looking forward to your progress reports.

Myles.

[KevinMC]

Steve- I thought about going

Steve- I thought about going the rod route, but I didn't want to have to fill in the big holes it would leave behind. Also, by using the spine I could ensure that the rotation of the formers was controlled, and it was really easy to cut the slot for it. (In addition, the fact that I happend to have some material on hand that would be good to make the spine from was a good motivator as well. )

Myles- The dw/foam is quite resilient, although if you press hard enough to compress the foam the DW will also crack, but that takes quite a bit of pressure. As noted before, my sanding pads are loaded up with 80 grit paper so it doesn't take much pressure to make them cut through the compound. I did leave a finger mark or two when picking up the plug without due care, but these are easily filled in. (The plug got really heavy once I started layering on the compound, so it became awkward to pick up and move around.)

The two extruded aluminmum sanding bars are model airplane products, put out by Great Planes, meant for sanding wings. I find the really long one (22") just perfect for doing the long straight parts of Oscar's hull. I've actually not yet used the smaller one on this project, but I'm sure it'll see use once the glass and primer are down. I use the drywaller's pad specifically for the spherical hull surfaces because the paper is supported by a 1/4" foam pad so it doesn't tend to leave flat spots while sanding. (The other trick I've found for trying to sand pherical surfaces is not to hold on to the pad with too tight a grip- use an open palm under the handle and only enough pressure to keep the pad in place.)

[steveuk]

Also, by using the spine

Also, by using the spine I could ensure that the rotation of the formers was controlled,

That's the beauty of this spine method.
Also you could easily draw the correct profile onto that spine board to ensure you are getting it exactly the right profile.

[KevinMC]

Well, I finished sanding down

Well, I finished sanding down the plug last night so it's all ready for glassing. Although the drywall compound is really nice to work with from a no-smell and water clean-up perspective, that crap gets everywhere when you sand it! Keep a shop-vac handy and use it frequently. Glassing begins tonight...

[guillermo pelaez]

Kevin,
Brilliant! I want to

Kevin,
Brilliant! I want to see pictures of that process! Thanks for sharing the experience. It seems you are having a very good pace. Any ideas on the electronics, ballast tank(s), etc?

[elec_tech]

Kevin,

Looking great!]

[color=#000000]Kevin,

Looking great!]

[KevinMC]

Guillermo- The glassing operation is

Guillermo- The glassing operation is really a no-brainer. I'll be covering the hull with one layer of 6oz loose weave cloth, then a layer of tight weave 3.5oz cloth. Rough cut the cloth to size, place it down on the work and pour on some slow cure epoxy resin and spread it around with an old credit card. Trim down the edges and have a beer. I probably won't get much in the way of "partially completed" glassing photos as this does tend to be one of the messier steps so I keep my camera away until I've cleaned up. I'll definitely get some shots for you when I vac-bag the appendages though...

Dan- I'd briefly considered lost foam, but for the number of people I've talked to that instantly responded with "You're doing an Oscar? I want one!" I figured I'd be a fool to make only one. All things considered, by the time the master is finished, it takes so little extra work (as compared to what's been done already) to make a mold it's worth going the mile.

[elec_tech]

Kevin,

Thanks for the info... another

Kevin,

Thanks for the info... another question if I may. Because you have a complete plug built now, how do you glass it without the spindle in the center to rotate it around? My plug is also complete and I was considering splitting it in half to glass each half. If you have a technique for glassing the complete plug, it would be appreciated if I could learn it from you.

Dan

[KevinMC]

Dan- Because of the way

Dan- Because of the way the hull necks down at the bow and again at the stern, I don't think it would be worth the frustration to try to glass it all in one piece. I've decided that I'll glass it top-half / bottom half, then left side / right side. I'll start on the top half with the 6oz cloth, and once that's dry I'll flip it over and glass the bottom half. I'll try to keep things such that I have a minimum of overlap between the two halves, maybe even leaving a gap between top and bottom. So I don't wind up with too much of a bulge (or divot) in the same place, when I put the the 3.5oz top-coat cloth down I'll cover it in left and right halves. This should minimize the amount of finish sanding I have to do. Also, the reason why I'm using an open weave cloth for my first layer is that it's really easy to get it to melt to the shape of the hull, even around the tip of the bow. Although not nearly as pliable, the closed weave cloth I'll be using for the top coat will minimize the amount of resin required to "fill the weave" after the cloth has been put down. (Just in case, I'll get some detailed photos of the cloth so everyone will know what I'm talking about with respect to open and closed weave.)