PylonWorld

Here are both sides. I forgot to mention that while the sides were in the shuck, I drilled 1/4" through the existing holes to a depth of 1/2".

The two sides are held together by 1" long 1/4" dowels.

Some reference marks have been made in the canopy area. More will be made for the thrust line, the wing location, and the stab location.

A 1/32" plywood cowl ring will be cut, and half of it placed on each side as a reference for the spinner. First I have to square up some stuff.

PylonWorld

Here is a top view.

Today I sanded, compounded and polished the Swee' Pea tail molds (again). I installed a torque rod on one side of the first Swee' Pea tail. Satisfied with the installation, I then drilled the bottom of the tail mold to accept the two torque rods during assembly.

Then I whipped this out. Tomorrow it hits the belt sander, and it should start to take shape.

PylonWorld

Here is a shot of the right side roughed out. I cut the top profile 1/8" oversize, so I could play around with the shape some before committing it. One thing I will be doing is adding a little concavity to the canopy/turtledeck. And obviously, the cowl will be made round.

Any comments?

PylonWorld

Here is the right side before final shaping. The left side will be shaped, and the cowl will be a little more rounded. Right now it's a little out of round.

PylonWorld

Here is the right side where you can see the shape a little better. The cowl ring has been attached, and the cowl sanded to fit.

The canopy will get a little skinnier, but I'm waiting until I do the left side, so that I have some wiggle room.

The fin/rudder has not been shaped yet.

This is the last picture for a day or two. I have to work on The Smasher, and I've got to layup a complete Swee' Pea, wing, tail, and all. Then I'll shape the H-1 left side. Since I'll have a Swee' Pea wing ready, I'll then fit the H-1 fuselage to the wing.

PylonWorld

FYI...

I had a little free time tonight, so I started shaping the left half of the H-1. I ran into a serious problem. I use a 1" belt sander for rough shaping. I had noticed that hand sanding the pink foam with 220 did not work well, and that it peels the surface, if it is smooth anyway. I had a 120 grit belt on the sander, and I though I would be smart and change to a finer belt, so that the amount of foam removed would be easier to handle. So I put on the Extra Fine 220 belt. As I started sanding the canopy area, with several inches of foam meeting the belt, the piece was yanked out of my hand. I resolved not to let that happen again, so I held on tight. It happened again. Then I started sanding some of the foam away from the tail. When I took it off the belt I noticed some dark streaks. The dark streaks turned out to be melted foam. It seems the finer the grit, the more heat generated. Be very careful when sanding pink foam, especially with a belt sander or disc sander.

I tried some Tri-M-ite 150 paper, and it does not work well either. The only paper that seems good for shaping the pink foam is 150 wood sanding paper. I have used 320 wood paper for very fine sanding with no problem, but I think it was because of using a very light touch. 100 grit can be used, but be aware that it hunks away the foam, so leave room for final shaping with the 150.

PylonWorld

I finished shaping the H-1 fuselage plug today. Because the fin/rudder is the plywood that provides the backing for the pink foam, I brushed some coating epoxy on the fin/rudder. Then I decided to just go ahead and coat most of the plug with the remainder of the epoxy. I'm still going to put .7 oz cloth with water based polyurethane on the plug for strength, but the epoxy will (hopefully) allow me to provide a better surface than the foam does.

I've decided not to put a wing or stab saddle into the plug for this iteration. If the plane works out, I will make a male mold (plug) and make the modifications to include the saddles. This requires more work to build a flyable plane, but it makes the plug easier, and allows for easy changes to the wing and tail.

I've done some pink foam combat planes from JK Aerotech and they came out fine for the purpose. That's where I came up with the idea for using pink foam for a plug. I think I will get results that are fine for a prototype, and it may be that making a male mold will allow me to achieve the quality I want, but I don't think pink foam is a good idea for a fuselage intended for production. It is too hard to get things exactly smooth. But you really can whip out a plug in a hurry. I could be making the mold as early as this weekend.

I'll post a photo tomorrow after the epoxy is hard.

PylonWorld

Here is a view from the left side. The thin layer of epoxy sealed the foam up real nicely, and I expect that the .7 oz cloth with water based polyurethane will come out much smoother because of the smoother base. It's really hard to get the sanding dust off of pink foam, and it tends to cause the cloth to have some bumps in it.

This view makes the radial cowl look huge, but in reality it doesn't look so bad in terms of obstructing airflow. It's certainly not the low forward frontal area of a Dago Red (foreground) ... we'll just have to see.

PylonWorld

Here are the two sides with .7 oz cloth applied with Olympic water based polurethane (WBP).

You have to be careful when applying the cloth. Areas that you have done can harden before you finish, especially on a piece this big. I needed a little more stretch in front of the canopy on one side, and the tail was firmly affixed, as was the nose area. So make sure you work out from the center, and that an area is complete before moving on. Or work really fast.

I made another 3/4" MDF handlebar using the original as a template. I got tired of changing it from side to side, and I knew I would need it when it comes time to prime. And that should be later today.

The cloth provides a nice foundation for the primer and any ding fixes. It turns out that sealing the foam with coating epoxy is a good idea. I ran out of epoxy and left two hand holds in the saddle area. They are not nearly as smooth as the epoxy coated areas. I knocked the fuzz off of the epoxy coated areas with 220 before putting the cloth on. I'm sure it saved me a lot of work. You could probably seal the foam with the WBP and get the same result, but I wouldn't use it directly over wood because of the water content causing warping.

Mluvara

My Feedback: (10)

Nice work on the threads and thanks for sharing Don. I now look back at our adventures building the Tsunamis, doing the threads, and have concluded that I was crazy . It's lots of work and I know that many benefit from it. Your racers look neat!

Michael

PylonWorld

I lightly sanded the plug halves after putting the .7 oz cloth on with water based polyurethane. I then sprayed the primer on ... boo-boo.

I should have brushed on another coat or two of water based polyurethane. This would have filled the grain in the cloth and I would not have been in pin hole city.

Since the primer was pretty thin, I got out a foam brush and just brushed on a coat of primer over the primer I had sprayed. Many of the pin holes were filled, but it will be difficult sanding.

The WBP tends to run off when you put a second and third coat on after sanding. I thought that going straight to primer would be a good choice. I'm going to do a test piece and mix some cabosil in with the WBP so that it is a little less runny and I'll let you know how that works out.

daven

My Feedback: (1)

You can also mix Micro Balloons with the WBP. It works well.

PylonWorld

Thanks Dave. I'll try the microballoons in the future.

The primer turned out to be ok. I just have to smooth out the edges because the primer doesn't brush real great if you're looking for a ready to paint surface.

The System Three water reduceable epoxy primer I'm using is nice except for the cure time. It takes 24-48 hours before it's readily sandable. I did some sanding today after leaving it in the hot box at a max temp of 84 degreees overnight. It's clogging the paper a little, so I'll give it until tomorrow.

The primer is a high build primer, and it soaked into the WBP adhered cloth very nicely. Now I have a firm surface and I should be able to fair in some dings (gouges) I made in the pink foam.

Since weight is not a concern, everything should be ok after all.

DHG

My Feedback: (7)

Don,

I've been fiddling with the Nelson (System 3) water-reducible concoctions myself, and managed to come up with a great substitute for that awful Bondo spot putty ... you know, the smelly reddish stuff in the tube?

Get ONE TEASPOON of the Nelson primer and dribble it into the bottom of a little plastic Solo cup ... mix it with 1/4 teaspoon of the primer activator, 1/2 teaspoon of bottled water, and 1 rounded teaspoon of Argo Corn Starch. Stir it up into a paste. Feel free to add a few drops of water if it's too thick, or more corn starch if it's too thin. Apply it with the edge of a credit card or (best thing) one of those small, triangular oil-painting spatulas from the art supply store.

Clean up with tap water, pop the Solo cup with any unused paste in your freezer until next time, when you can thaw it out and re-use it.

The stuff does take overnight to cure, but it doesn't shrink & crack like the Bondo.

I bet that would fix those little gouges in the foam.

daven

My Feedback: (1)

I have used the system 3 paints, and honestly don't care for the primer.

You can use Rustoleum "Automotive" primer with this paint. The Rustoleum dries fast, and you can be sanding in less than an hour. You will need a couple cans for each project, but thats still relatively inexpensive.

The system 3 paints do work with the Rustoleum, its the only non-system 3 primer they recommend.

PylonWorld

Dave,

I like the primer, except for the cure time. It does require that you sand at the right time. If you wait too long, it gets too hard to sand easily. If you sand too early, it clogs the paper. But from about 36 to 72 hours after application, it sands ok. If I hot box it at 90 degrees, I can sand it after 24 hours, but that's a lot longer than 1 hour. I do like the adherence ... I've had no problem with it coming off ... and I do like the high build properties. I'll give the Rustoleum Automotive a try.

In terms of the System Three paints, I like the water cleanup and reduceability. I also like not having to wear a respirator. But I don't like the color selection, especially the lack of metallics and neons. I don't like that it dries in a thin film so quickly. While you can clean up with water, any area on the gun where the paint formed a thin film is next to impossible to clean. I like the price and the ability to buy small quantities at a reasonable price. So far, I'm not real happy with it for painting in the mold. It flows out ok on sanded surfaces, but it's hard to get it to flow out on slick surfaces, unless it is over itself in less than 18 hours or so.


Duane,

Thanks for the suggestion. I had contemplated adding Q-spheres and some cabosil, but haven't tried it yet. If you promise the corn starch works, I'll probably go straight to that.

PylonWorld

Here are the primed plug halves in the hot box for curing the primer.

The other stuff is The Smasher Q-500 related.

PylonWorld

For those of you who had been following this thread, I just wanted to let you know that the project did not die. I just had some more important stuff that needed attention.

Since I'm getting ready to do another pink foam plug project, I want to finish this one up so that I know what kind of results to expect.

I put the final coat of primer on it tonight.

Mold making should begin some time next week.

PylonWorld

Here is an article about the Hughes Racer Replica Build Story.

Lots of good photos, but the easiest way to view the whole gallery is to click on Hughes H-1.

PylonWorld

Here's a front quarter view of the plug halves together.

I painted the plugs with the same paint I plane to use on the first one that will use the full scale subject's colors. The Nelson paint is not available in metallics. But my new digital camera died and these photos are not a good representation of the actual color.

I like to paint plugs in a color that I expect to use. This particular color has some weird characteristics. It looks like a nice pale gray as you put it on, then it starts to get a blueish tint as it dries. This lead me to overcoat it and I got a few runs that will have to be sanded off. I was also using a new HVLP gun, instead of the Paasche airbrush I usually use. I like the new gun though, and it's relatively cheap.

PylonWorld

Side View

PylonWorld

These are the 3/4" MDF "handle bars" that I used for handling the plugs. It doesn't take much to dent or ding the pink foam, so I rarely touched it, except to feel contours.

The mounting boards are primed and painted.

I'm going to stick the plug halves to the boards with double sided carpet tape.

More than likely the plugs will be destroyed when they are removed from the molds, so I wanted to show them in the "before" state.

PylonWorld

Here are the plugs sanded, compounded, and polished. And mounted on the backing plates. I used carpet tape, and while it was simpler than gluing them down, I will use another method next time.

I hope I don't forget to wax them before I start making the molds.

My old digital camera is so old that it doesn't have a flash, so I used some external lighting to show the color and details a little better.

Mluvara

My Feedback: (10)

On a sad note, the aircraft and pilot were lost earlier this week when it crashed enroute back home from Oshkosh.

PylonWorld

That is a sad note, indeed.

I had a failure of my own with the Hughes plugs today. The carpet tape stuck to the side of the plug that didn't have the paper template, but did not stick to the side that had the paper template. And it wasn't stuck all that well on the bare wood side, either.

So I had to take the plugs off the plates. Only a minor ding here and there, but while trying to remove some residue, I dented the bottom of one side with my finger.

Originally I had planned to glue them down with 3M77, but I went down the carpet tape path. Don't do that. After I cleaned everything off from the mold release treatment I had already begun, I wet sanded one of the mounting plates with 600. I didn't compound it because of the oil in the compound. I cut 4 pieces of masking paper and traced the plug, and cut all 4 masks at once. Then I attached one mask to the plug, and one to the mounting plate. I sprayed both with 3M77, and let it tack. Then I attached the pieces. We'll see if that holds overnight, and if successful, I'll do the other side.