CoolerByTheLake

Going to glass right over plug and use lost foam method. I'v been told, by a few who do make there own molds that 3 layers of 3oz glass should be fine. It will also have carbon fiber and tow in all high stress areas. Several have done this and worked well. Not making a mold, too costly, and easier to make another plug. So, is 9oz of glass going to be strong enough?

wyowindworks

Strong enough for what application and size?

CoolerByTheLake

It will be a jet fuse for a Dynamax fan. The fuse will be approx 62" long, 8" high , at widest point,ducts about 101/2" . Similar in shape to most 5" fan jets.

ByLoudDesign

You can use poly rod to form strengthening ribs; it comes in different diameters and is use as backer for caulking, along the form, and glass them over! Cheaper then CF, On big boat molds we use cardboard tube and a layer of chop and 24 oz. fabmat.

SCALECRAFT

My Feedback: (13)

The method posted by BLD, if used properly, is one of the best and cost effective ways of reinforcement. Blows carbon fiber away.. Now if you use carbon fiber on BLD method, even stiffer.

Steve

sidgates

My Feedback: (2)

I think 3 layers of 3 oz is a little light for jet.

I don't consider myself an expert on molding but I have been fairly successfull in my first attempt at a fuselage. See my work at: http://www.sidgates.us/HOBBIES/F-94C/F94C%20PROJECT.htm

I highly recommend you check out my glass covered foam bulkheads to get the fuse ridgid and keeping it light. Any bulkheads that mount the wing should be stronger than foam. I like end grain balsa covered with carbon fiber instead of glass cloth.

If you have any specific questions PM me or on this thread.

CoolerByTheLake

I have be told that 8-9 oz/sq/yd should be strong enough. Now consider that there will be 3'' carbon fiber in nose gear area, 2 strips, each side of center, from intakes rearward, past both formers for wing and fan mounting. There will be a access hatch, to get at fan and other component. Where the 2 formers will be,wing and fan mounting, there will be carbon fiber from side to side. Carbon tow as needed in the exhaust tube.

SCALECRAFT

My Feedback: (13)

Note that if you put carbon fiber or any reinforcements where you have bulkheads or formers, you don't need to stiffen that area. The formers/bulkhead does that.\

I would put carbon/kevlar in areas that need support, but have no formers.

The model is 48" span, all composite, OS .46VF powered, retracts, arox 7lbs. The entire fuse rear of the canopy is only supported by composites till the rudder post.

Fuse shapes play a very large roll in what is needed where.

New project, 90mm F-104 plug



Steve

CoolerByTheLake

Thanks. Here's my project- a replica of a Y/A Starfire. I'm going mostly from the many build photos I have from several build threads on RCG. My plug, still in shaping stage and a couple to show some of the carbon fiber locations.