P-51D Mustang

[lastvautour]

Great info Ken. Please place your plans the tool section. Looking forward to more progress reports.

Lou

[Model Maker]

No that Fall has arrived, time to switch back to completing the Mustang build.

The first picture captures my approach to fabricating the manifold exhausts. A thin piece of poplar was cut and a series of holes drilled (bottom left)
The material between the holes was removed (top left) using an Exacto knife. A set of manifolds was assembled using K&S brass tubing for the exhausts which were epoxied in place. Assembling the manifolds adjacent to each other allows symmetry checks to be performed during the gluing process

The second picture shows the recess carved into the fuselage to accept the manifold assembly. It is carved with an inwards taper to provide the requisite mounting angle of the manifold and exhausts.

The third picture shows the manifold glued in place.

The fuselage is now ready for final sanding and to have the tang removed.

[lastvautour]

Very realistic exhaust Ken. What type of adhesive are you using?

Lou

[Model Maker]

Lou:

I use LePage's 5 minute epoxy to glue the brass tubes (exhaust pipes) into the slotted hole. Epoxy is the best option to facilitate the required metal to wood bond but any 5 minute epoxy should work well. I place the wood on top of a sheet of wax paper which prevents any epoxy on the bottom from sticking to anything. It also provides a smooth surface for the epoxy to set up against. I don't use the slower drying epoxy as it may all run out before setting up. Once the epoxy has set, I then attach the manifold to the fuselage with regular carpenter's glue since it is primarily a wood to wood bond. I could have used epoxy for this as well, but I prefer to work with the regular carpenters glue whenever possible due to the the ease of cleanup and the fact I don't need to wear protective gloves. Once the carpenters glue has dried, I use some wood filler to tidy up the joints / manifold profile as required.

-ken

[lastvautour]

Thanks Ken.

Lou

[Model Maker]

Summer's over so it's back to the "Elf Shop". The 3 Mustangs are in different states of priming and sealing.   Thought I'd share my sealing and priming approach below. I'm horrible with rattle cans so I like to brush on the primer coats to allow wet sanding. Then when I am happy with the sanded primer, I'll switch over to the air brush to apply the top coats of paint and varnish.

The lowest Mustang (still with the natural wood finish) has a sealer coat of varathane, mixed 50 / 50 with varsol (paint thinner). Since the body and wings are pine, this should prevent any pine pitch from migrating through the paint and hopefully seal the moisture level of the wood. The thinned down varathane also penetrates the wood more than some other sealers.

The middle Mustang has been sprayed with Zinser BIN primer. This is primarily a shellac primer which is tinted white. The shellac also provides a barrier to the pine pitch. But most importantly, the shellac provides a great base for the subsequent build coats of primer to adhere to. It is however, a very thin product so is not appropriate for build coats to facilitate wet sanding out blemishes.

The top Mustang has several coats of Zinser BIN 123 water based primer. I typically brush paint two coats of white and then add two coats of grey before wet sanding.  BIN 123 is  very thick high build primer. The two coats of white serve as a warning when I am wet sanding. If I sand through the grey and expose the white, I stop sanding and add another layer of grey if required to build up the defect or add some glazing putty and then re-prime. I leave the propeller hubs white as this seems to provide a better background for yellow paint applied to the propeller tips.

One thing I miss is the self leveling capability of the old alkyd primers. Today's alkyd primers seem to dry too quickly and don't level. The BIN 123 is an acceptable leveling product and wet sands well. However, it is not good if the control surface lines need to be re-scribed as it is rubbery (even when cured) like most water based paints and primers. However, during some recent home decorating, I came across a great primer. DULUX water based alkyd primer. It seems to be very good at self leveling and leaves very few brush marks. It also behaves in a similar fashion like the old alkyd primers when I need to re-scribe a line. The only downside is it's only available in gallon (ie 4 litre) cans. Since I had some left over from my decorating, I diverted some into a couple of smaller sized cans and had one of the cans tinted grey to provide me with the ability to carry on with the two color primer approach.

I'd certainly be interested in the sealing and primer techniques used by others.

- ken

[lastvautour]

Thanks for the instructions. The Mustangs look great.

Lou

[Model Maker]

Thanks Lou.

I'm looking ahead and have a question related to which aluminum paint members use. I am not good with spray cans, so will be staying away from them. In looking at the internet, Alcad II seems to be one of the preferred metalized paints. But I'd like to stay away from the lacquer if possible. Any other suggestions?

[Will]

I usually brush paint and have had reasonable results with humbrol 11 silver or Revell (of Germany) 66 Aluminium enamels.  My other choice available locally is Games Workshop Mithril Silver (its an acrylic) which matches aluminum dope, they probably have a brighter silver in their range.
Alclad is popular with the local plastic assemblers but needs perfect finish and gloss coat, may not be great on wood?
I once primed our new hardwood front door with Aluminium Wood Primer, gave a great silver finish though I was nearly blinded when the sun came out!
Will

[lastvautour]

Metallic finish are hard to do. I have tried a few approaches, but so far the rattle can has given me my best finishes.

Lou

[Biggles]

Wing being set up to use back stop to plane wing taper.

The first picture shows a standard bench hook along with the backstop. In order to use a plane I required a very low back stop to allow the plane to travel over the stop to create a smooth taper along the full length of the wing. After several iterations, I finally landed on recessing a 3/4" x 3/4" piece of hardwood into a corresponding groove in a 1-1/2"W x 5-1/2"T piece of wood of appropriate length. A couple of thin wooden shims are installed at the bottom of the groove to raise and lower the backstop as required, depending on the final thickness of the of the wing tip.

The second picture shows the backstop installed on top of the bench hook. The wing is ready for tapering using a block plane which seems to work well for 1/32 scale wings. I have a couple of block planes, but have found the Groz BP605 low angle block plane to be ideal for this work. It's a little narrower and lighter than many of the block planes which allows me  taper and also shape the profile of the wing after the tapering is complete. It's not an expensive block plane, but does seem to do the job provided you keep the blade sharp.

If folks are interested in the backstop jig, I can post the plans for it.

This is how i do it to!

[buccfan]

Mustangs look great Ken, I know what you mean about the Zinser Bin123 being rubbery even when dry, we used it on a lot of tongue and groove cladding. Regards Paul J.

[Model Maker]

Gentlemen: - Thanks for the feedback.

Biggles - glad to hear I am not down a path which others have abandoned.

Paul & Lou - Thanks for the encouragement. Dare I say the hard part is yet to come? - Painting!!

Lou: In viewing your various threads, you certainly seemed to have mastered the spray can. I just can't get the hang of it. I suspect I am spraying too close in order to minimize over spray. I used to have the knack as a kid when I would spray my model cars with Testors. Somehow I don't seem to recall the pressures in the spray cans being as high then, so there was less overspray. But maybe the years are clouding my memory.

Will: Thanks for the great info on metallic paint options.

I don't think there would be an issue with Alcad on wood provided the wood has been properly primed and meticulously wet sanded. I've read Alcad requires a base coat to separate it from the plastic to prevent the lacquer reacting with the plastic. So I would assume applying the requisite black undercoat to a well primed solid model would provide the same base as spraying a plastic model. The Alcad shouldn't notice any difference in the base it is bonding to. But as you said, the solid would have to be perfectly sanded just as with the plastic models since Alcad highlights imperfections.

In performing some subsequent searches, I have found Vallejo has recently introduced a new line of water based metallic paints which seem to be receiving good reviews. Like Alcad, a shiny black undercoat is required to assist in creating the shine. I think I'll give these a try on at least one of the P-51's. I've also discovered Createx has a couple of water based metallics in their "Wicked" paint line so I might try these as well.

And of course, I'll try one of your recommendations. Not sure which one yet, but I'll let you know. It'll either be the Humbrol or War Games since both are locally available.

I'll keep track of my learning's in the water based world of metallics and possibly start a separate thread if I have success. If things don't work out, I can at least resort to one of the great benefits of solids. Just sand the problem away!! I can then paint all three with one of the recommendations from Will 

-ken

[Biggles]

so there are 3 p-51 s?
the wings for me are the hardest part along with painting.

[lastvautour]

I must try the gloss black undercoat on my next metallic finish. Thanks for the tip

Lou