Hey, folks. A while ago I started cleaning up a set of plans for the Free Plans collection on this website, and identified a number of errors. I believe I have identified and corrected all of the errors, and to confirm this I am building a full-scale cardboard mock-up of the pre-dreadnought battleship Mikasa using the materials and tools I have access too in my dorm. The mock-up is about 1/3 done now, and I'm starting to think about what comes next. Several possibilities have come to mind, including turning the mock-up into a plug for a fiberglass hull, or turning the mock-up into a pattern set for a fine wooden hull. I can do one or the other, but not both. Both options are intriguing, and I have several questions. 1) Is it possible to build a plug for a fiberglass mold using cardboard ribs? If so, what additional materials are needed? foam? plaster? planking? 2) If I do build a plug for the Mikasa, are people interested in it? If I make a pattern set for a wooden hull, would people be interested in it? 3) one of my goals is for the Mikasa to use the standard Big Gun cannons from BDE, now Strike Models, without any modifications to the cannons. Unfortunately this requires approximately 1/8" extra depth more than true scale. Do the various fast gun clubs (IRCWCC, MWC, Treaty) allow extra depth for a 15,140 ton, 36 inch long predreadnought battleship?
This is not on the MWCI shiplist and may not be MWCI legal as it launched before 1905 (launced 1900). H. Warship Classes 1. Unless a ship has been specifically exempted in subparagraph a. (below the table), the characteristics listed in the following table take precedence over any values listed in the MWC Ship List. Only ships which were launched between 1905 and 1946 inclusive and were completed will be legal to model (refer to MWC Ship List for legal ships). Listed below are the authorized classes and the offensive/defensive units allowed:
My Dad was involved in boat manufacturing in the 70s for Glastron and Skeeter Bass boats. He told me the way they would make a mock up hull would start with the ribs and then stretch a t-shirt over it and then fiberglass that. I dont remember much other than that but it might get you started. How the mold was made so smooth I am not sure. Maybe he waxed the t-shirt after it was stretched? Im not sure.
I think 1 of that class was launched after the "leagal" date. You'd need to do some more chekcing. You can easily turn the mock up into patterns for a wood hull. You seam to know how to do that. I have seen a how to someplace, maybe here, on using carboard ribs as the skeleton for a plug. Next step was to fill in the spaces with pink foam and sand to shape. Then cover everything with sheetrock mud, final sand that, then I think they sealed it with something, maybe it was just mold release wax. I've also heard people skip the sheetrock mud and cover the ship with plastic food wrap. After the fiberglass mold is made the burn the plug to get it out of the mold. The best way to make a plug is with a big wood block. That's how BC & Strike get their new hulls. But that takes a lot more money, about $850 per plug. Lots of tools and skills are needed. At some point your mold will get old or break, then you'd like to still have that plug to make another.
I wonder if it's possible to use a wooden hull (carefully constructed for correct scale) as a plug to make a mold, without making the wooden hull illegal for use as a combat ship.
Yes, wooden plugs are often made and a two piece fiberglass mold made from it. Remember to calculate the thickness of the balsa on the outside of the fiberglass hull. Marty
We have some of the plugs that were used to make our molds, and we've never heard of having to burn out the plug. We are getting new molds made from plugs, and no burning will be involved.
"burning out the plug' is a one off plug made from something like foam. It is made like a regular plug, then used to either make a mold or glassed to make a hull. One the mold or hull is made, a chemical like gasoline or acetone is used to melt out the foam.
I have identified all of the errors in the original plans, and I know enough to correct them. However, correcting the plans themselves will actually take more effort from me than building a hull. As far as making a pattern set, for the most part that shouldn't be too hard. I would need to finish my cardboard mock-up in order to get an accurate deck profile, and then I'll need a scanner to digitize the correct deck profile and the corrected ribs. The tricky part will be the ribs and impenetrable areas. Since different formats have different rules on rib spacing and bow and stern impenetrable areas, the best I can do is include all the ribs I have and let the builder decide which ones to use. I would also include patterns for the superstructure, too.
You may have just answered your own question. If you make a plug from your frames, you can share your work with no worrying about different rulesets.
It is possible to do it I think. I make my plugs from balsa sheeting used to create a skeleton of frames covered in 1.5mm balsa and bondo ccoated then sanded then resin and sanded till smooth, then when really happy with it coat in mould release and lay a mould over it with black pigment in the resin and once cured I usually have to destroy the plug to get the mould.
My 1/144 Pommern plug is balsa-on-cardboard frames, like Mick says he's done (haven't sealed it with epoxy yet, still a WIP). I assembled the frames securely, and used a hot glue gun to get the balsa to stick to the carboard. If the plug dies, I'll be okay, since I will get what I want from it.
When I make a plug I make it from 2.5mm balsa frames and 2.5mm balsa spine section with a strip of aluminium right angel from bow to stern either side to make sure they stay true. If I could add a photo I'd add one of my plug for the Mauretania while it was under construction. Of all the moulds I've made only 6 plugs have survived, the Normandie battleship, Mamiya Maru, Tribal class destroyer, Tone light cruiser and Narvik Class destroyer. Of these only 2 were immediately usable to make another mould if I'd wanted to and the rest would have needed repairs to reuse. I make the plug cheaply but strong as its just a means to an end.
