From David M :
Hi Bob,
I am building a tribute model of the B-24J my dad, Walter R. Miller, served in as Bombardier / Navigator in WWII. I am using a Guillow’s B-24 1/28th scale balsa kit as the basis of my project. Attached is a photo of my dad and his crew mates in front of their B24-J, #109. With the help of some very kind members of the Commemorative Airforce, I have learned much about my Dad’s particular B24 which will help me greatly with my project.
Mostly because of the rather large scale of this model, I have some challenges, and I think some opportunities to achieve the most realistic looking model my skills will allow. I am an experienced scale model builder, most recently in the world of scratch built narrow gauge industrial trains at 7/8″ scale (13.7:1), mostly in styrene and brass. I’ve built my share of balsa aircraft models back in the day, but it’s been awhile. That being said I am very excited about my B24-J balsa aircraft project for this winter!
I have read with great interest your blog posts about your Guillow’s Hellcat RC Conversion project. My model won’t be a flying model, but I plan to use a method similar to the balsa sheeting you describe, followed by Silkspan covering. I then plan to replicate (as best I can) the appearance of individual sheets of mill finish aluminum, in an effort to look like my Dad’s aircraft. Again, I’m not concerned with flying characteristics of my model, just realistic appearance.
My questions are as follows:
1.) Silkspan Navy Dye: Did you dye your Silkspan navy blue as part of your ultimate finish color process (navy blue), of do you find the blue coloring helpful as you align and overlap sheets of Silkspan, or both?
2.) Roket Rapid vs. Aliphatic Resin: In your Hellcat build blog, your mention at the beginning of installment #52, the use of wet balsa sheets and the use of Deluxe Masters Aliphatic Resin. Later on in the same post you show the use of Roket Rapid CA glue, used to attach (apparently) dry balsa sheet to fuselage and wing stringers. Would you be kind enough to clarify where you see benefit to these two methods.
3.) I’m also wondering if you have any suggestions to achieve the appearance mill finish aluminium with rivets, and individual aluminum panels etc. I have some ideas, but I would love to hear how you might go about this.
Thank you so much for posts, as I’ve found them very helpful!
In the case of my Guillow’s Kit 1005 Hellcat, for which I made up that lot of dark blue dyed silkspan, both conditions apply. With this model, as with several others I have written about, plain white silkspan dyed in an appropriate color and finished with clear dope or an equivalent is the best way I have found to get a sort-of-scale color finish with a minimum of weight. As it happens, when the adjoining edges of colored silkspan pieces overlap they create a more intense /darker line that does a fine job of representing a panel line or overlap. You can overlap or edge-butt to get lines of varied width or nearly invisible joints respectively depending on the effect you want to create.
You are correct in observing that I take advantage of some of the properties of Roket Rapid and of Aliphatic Resin that are very different. As it is water-based, the Aliphatic Resin is a natural for use in using pre-wetted balsa sheet to cover/skin a fuselage that is all compound curves. It does indeed penetrate the wet balsa better than dry wood and its relatively slow, evaporative curing/drying allows plenty of time to get everything aligned exactly and then does a good job of matching the speed at which the wet balsa itself dries. The downside of doing it this way is that it’s necessary to do that all-the-way-around tape-wrap to keep it in place. An alternative method is to use the Roket Rapid (medium -cure/open joint) product to fix one edge of the working piece to an appropriate base like a top stringer or leading edge, then spray the partially-attached sheet with water
In the case of my Guillow’sKit 1005 Hellcat, for which I madeup that lot of dark blue dyed silkspan, both conditions apply. With this model, as with several others I have written about, plain white silkspandyed in an appropriate color and finished with clear dope or an equivalent is the best way I have found to get a sort-of-scale color finish with a minimum of weight. As it happens, when the adjoining edges of colored silkspanpieces overlap they create a more intense /darker line that does a fine jobof representing a panel line or overlap. You can overlap or edge-butt to get lines of varied width or nearly invisible joints respectively depending on the effect you want to create.
You are correct in observing that I take advantage of some of the properties of RoketRapid and of Aliphatic Resin that are very different. As it is water-based, the Aliphatic Resin is a naturalforuse in using pre-wetted balsa sheet to cover/skin a fuselage that is all compound curves. It does indeed penetrate the wet balsa better than dry wood and its relatively slow, evaporative curing/drying allows plenty of time to get everything aligned exactly and thendoes a good job of matching the speed at which the wet balsa itself dries. The downside of doing it this way is that it’s necessary to do that all-the-way-around tape-wrapto keep it in place. An alternative method is to use the RoketRapid (medium -cure/open joint) product to fix one edge of the working piece to an appropriate base like a top stringer or leading edge, then spray the
, brush Aliphatic Resin onto every joining surface inside the joint, and then hold the assembly in place during drying with building weights or more tape. You could also attach the entire piece of wetted balsa sheet in one step by applying Roket Rapid to all the joining surfaces and then grab-and-hold the entire assembly while it cures…IF you are confident you can position and hold it accurately enough. In the end it comes down to a judgment call on the builder’s part to pick the best technique for the job at hand.
In my opinion, and as you suggest, the best way to replicate a sheet aluminum surface is to use sheet aluminum. Some of the popular plastic coverings come close here, but require some extra effort to get it right. If you buff the outer/non-sticky side of a metallic trim sheet in one direction, as if representing a consistent grain in the material and then cut individual scale-panel-size pieces and bond them to the model surface with the grain in alternating directions, you can get a good metal-skin effect. There are also several model airplane products on the market that use real aluminum sheet to do the job. Check out http://www.flitemetal.com/ for a good look at what I’m talking about.