1/72nd scale alfa class ssn

[the dark knight]

well, i decided to avoid confusion, i would break alfa into her own thread. so far so good! just have the bow left, and the first layer of glass will be done. whew.

lets start from the beganing.... started off with the left over 2' foam from my IXD2. cut it out on my band saw, and shaped it with a wood rasp and 60 grit sand paper


then shaping begain


then i looked at the plans and photos, relized the alfa has a small ledge around the tower in the rear... so i dug out my drywall compound and begain shaping that

[the dark knight]

Re: 1/72nd scale alfa class ssn

so i decided on this one to try the duct tape method of sealing off the plug


it sort of worked, the fiberglass is causing wrinkles in the tape... not a big deal, not any major distortions yet. so i started at the conning tower and fiberglassed it first


then turned it over, and glassed her belly and stern



thats where she stands now..... next is the bow!

[the dark knight]

Re: 1/72nd scale alfa class ssn

well, here is where she sits tonight. will do another coat here shortly.



here is what ive learned! i bought the other kind of resin... not epoxy. oh well. lesson learned on the conning tower of the IXD2. duct tape is effective, but on the IXD i may do 2 layers of tape based on the behavior of the tape on the alfa. also discovered alfa consumed alot more glass then i thought, which means i didnt have enough for the IXD. also learned a resperator is a must when working with fiberglass resin of this type, and rubber gloves are a must! updates as i make them!

[the dark knight]

Re: 1/72nd scale alfa class ssn

coat # 2 is almost done, bow will be done next!





i am pleased to announce the bow has the second layer on it. here is what im thinking.... i currently am at the correct scale diameter with 2 layers of glass and cloth. yep, i miscalculated how thick it would be. so, i think i am going to smooth out what is there, seperate the hull, remove the foam and do another coat inside the hull. thoughts? suggestions?

[jeffrey j]

Re: 1/72nd scale alfa class ssn

looking good Jon.

[jeffrey j]

Re: 1/72nd scale alfa class ssn

hey Jon, one more coat on the outside isn't going to an issue, imo at least, looks great, buy the time you sand the entire thing smooth you will have removed extra material anyway. I am going to be running a 1/72nd Alfa prop on my Sturgeon,, lol,, kind of a Russian, U.S. combo sub. Jeff Jones

[the dark knight]

Re: 1/72nd scale alfa class ssn

cool! thanks Jeff! your Sturgeon is turning out great, been following your threads on it! my major concern is i am loosing my walkway around the conning tower slowly... if i sand it smooth and do another layer im worried i might loose it..... ill see where i stand after i sand it down. thank you again sir!

[Rick Teskey]

Re: 1/72nd scale alfa class ssn

Here are a few things I have learned when doing a plug this way.
I do not do the one off ,melt out the foam, etc method as I always just make a mold of the finished plug.
When working with styrofoam you can rough/ semi finish the shape as you have done ,then coat in epoxy ( west system) which will not harm the foam plug and with a little abbrasion for tooth, bondo can be put on top too fix any areas that need attention / fine tunning.
Now as for sealing off your plug as you have done, next time use the aluminum duct tape which should not wrinkel as the cloth based stuff does and when done creativly can represent pannel lines.
My prefered method is when using the less expensive polyester based resin is too seal off the plug with a coat of white carpenters glue right over the foam worked well into all the nooks and crannys that way when fully covered and dried, a thin coat of bondo can be applyed with out any melting of the foam, then sand and fill and repeat and finish then make a parting board and start the mold layup after suitable waxing and mold releaseis applyed too the finished plug.
It maybe another step too make a mold but the work in my opion in the long run is less than the shape cover melt , dig scrape method as when pulled from the mold you have a nice surface too play with.
Rick

[the dark knight]

Re: 1/72nd scale alfa class ssn

ive been tossing around the idea of molding this when i get it smoothed out.... however, i dont wish to make a mold if there isnt intrest in atleast a few copies being sold to recoup the molding costs.... i havent decided yet. thanks for the tips Rick, i will try out what you suggested on the IXD2. as for the alfa, here is where she sits now. waiting on the resin to cure so i can resume smoothing it out.

[Rick Teskey]

Re: 1/72nd scale alfa class ssn

O.K. carry on.
Another quick tip, when trying too seat a part on the plug i.e sail or planes and rudders , if you wrap a bit of sand paper around the area location for part and work a block of foam back and forth it will take on the contour of the hull then you can cut the styrofoam too shape and it will seat nicely.
Give mold making a go you never know you might loose you boat or there maybe interest in the hull even if you do not sell one for months or years you have it ( I have some molds that are 20 years old now and I only sold 1 last year), sure there is the out lay of $100.00 for materials but you will have a nice hull of constant thickness and no puddels of toxic messy goo too deal with .
If you have any questions or want any suggestions , just ask, so go ahead and finish the surface as nicely as you can even if it take several rounds of filler and primer and putty the more effort you put in will pay you back 10 fold.
Rick

[the dark knight]

Re: 1/72nd scale alfa class ssn

would you suggest rubber like rebound 25? or a fiberglass mold?

[thor]

Re: 1/72nd scale alfa class ssn

Definitely Fiberglass!!!

[the dark knight]

Re: 1/72nd scale alfa class ssn

will that allow me to keep details like scribe lines? or should i just do a smooth hull and scribe it after?

[thor]

Re: 1/72nd scale alfa class ssn

The answer to your first question is yes! The answer to you second question is "it depends".....

It depends on what you intend to do with the model and the process you intend to use to get it to the point of being able to mold it. I would recommend coating the model with the resin of your choice, sand it smooth and use the appropriate finishing process that you prefer. Pull a mold off of it at this point and then scribe and detail it up as you wish. If you intend to do a one off, you are done. If you intend to sell a few, then you have another molding process to go...

Matt

[the dark knight]

Re: 1/72nd scale alfa class ssn

cool! thanks Matt! what would you recomend as a mold relise agent? i have enough glass here to lay up a mold.

i guess i will mold it... its turning out really nice, and i guess another alfa kit wouldn't hurt anything. thanks for your insight so far Matt!