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Old Jun 24, 2011, 01:52 PM
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This would be a typical first cloth layer. This is continuous strand surface veil or mat. It will stop the heavier weaves yet to come from showing through your surface coat over time. No need to apply it to the flanges: just the part.

You may be tempted to use a chopped strand mat, but the binder in it will react negatively with epoxy resins.

I will now wet this out with laminating resin.
Aeropoxy 2032 with a 30 minute hardener.

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Old Jun 24, 2011, 07:40 PM
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I double dog dare someone to try this on their own! lol

1st layer of 9 oz/yd^2 almost 15 hours into things - I haven't stopped for a coffee yet....


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Old Jun 24, 2011, 10:11 PM
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So now it's just 7 more layers....still haven't managed to eat...as soon as I finish at one end, it's time to start at the other again...

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Old Jun 26, 2011, 04:39 PM
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Well, everything seems to have turned out quite well. The only thing that I'm not overly happy with is the sealer on my wooden registration keys didn't handle the job. Next time I'll use some Kermit the frog eyes from the craft store probably. This time, I'll use the back up plan around the perimeter.

Anyway, here are some early shots. I still have a lot of clay to clean etc., but hey, pictures are cool on a Sunday afternoon too...I'll have more to say later, but I need a coffee.










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Old Jun 26, 2011, 07:16 PM
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Looks like you are using Aerpoxy based resins. From the pdf, is PT1414 the tooling gel? And what is your layup resin? Where did you purchase the tooling epoxy in particular from?
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Old Jul 04, 2011, 01:02 PM
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Yes PT-1414 Part A and Part B are the tool surface coat resin and hardener.
The laminating resin is also Aeropoxy but is PR2032.
Neither are difficult to find. Composites Canada is a quick easy solution if you're around Toronto.


Alright, I've had a nice little rest so I thought I should document some things here while I've got a moment.

Since making the fuse mould in 16pcs that each contained 13 layer laminations, at about 3 hours each, I decided that I needed to explore methods for not only speeding things up, but also reducing material costs. As a home hobbiest, you know that the further you can stretch a buck, the better. And afterall, we're building model airplanes here....

The first thought, as silly as it sounds was to go to a bigger brush. Well, that means mixing larger batches, which means a new scale. It also results in using about twice as much resin, but that's another story.

After some thought about rigidity of the tool, I came to the conclusion that what was needed, was much the same thing that's needed in a wing; a spar to take the bending moment produced along the length of the wing, and something to resist twist.

In the end, by using an integral fibreglass outer shear flange around the tool perimeter, and also incorporating the aluminum extrusions at acute angles in the tool face, I was able to cut the 13 layers down to 6 in the tool face and only 4 around the vertical perimeter shear flange.

More substantially, in terms of cost, I went from 2 gallons of laminating resin down to under one. In ballpark figures that's about a 60% savings in the material cost of this tool. The labour savings, although I will not quantify it here because it would require me to assign some certain degree of value to my skill level, was priceless to a guy who couldn't feel his legs after laying down each layer.


What does General Bugsy think of our new toy?
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Old Jul 04, 2011, 03:12 PM
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He looks extremely pleased!
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Old Jul 07, 2011, 08:19 PM
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...while I wait for an epoxy shipment....I've been having some fun!

This project now has an official bumper sticker!

http://www.zazzle.com/two_bulldog_br...58242949723849

I can't wait to get one on the truck

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Old Jul 07, 2011, 10:14 PM
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He looks extremely pleased

Made me take a second look and my you're right!

I think the term is "Happy".
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Old Aug 02, 2011, 05:00 PM
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Well, the trial epoxy from my newest trial source has arrived. Online ordering and shipping from within Canada was just too much to resist. The price reduction helped out too.

Now let's see what this stuff does. It took a month to get here (maybe longer, I don't care to try and recall - I needed a break anyway), but now it's time to get back to work!

I may use this gallon with the slow hardener to make a few fuselages to sell before I get to the next upper section of the wing mould. This is a good way to cover the costs of the project. If I'd known then, what I know now, I'd have made the canopy and cowl moulds first, sold a few, and then I'd have needed less money to put in up front on the Two Bulldog P-40

...well, here's what it looks like...







...and here's where I got it http://www.miapoxy.com/p-26-miapoxy-...tem-clear.aspx
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Old Aug 03, 2011, 12:33 AM
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Quote:
Originally Posted by Slow & Low View Post
Well, the trial epoxy from my newest trial source has arrived. Online ordering and shipping from within Canada was just too much to resist. The price reduction helped out too.
Sounds great! Care to elaborate?
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Old Aug 17, 2011, 03:11 PM
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Over the course of the next several days, I hope to layup another P40 fuselage in the mould. This revision will incorporate a 1/4 inch ply firewall, and also a flange on the tail section to ease assembly for whomever should get their grubby little hands on it. lol

I'd like to end up with a sheet metal template for producing future firewalls as well.

I got these two sheets of ply for under $5 each at a local woodworking supply outlet. Oh yes, one sheet is 1/4" and the other is 1/8": both birch.



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Old Aug 18, 2011, 11:24 AM
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Oh boy, my old friend is back...you know, this is one of those pictures that is hard for me to believe - yep I'm that guy!! lol

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Old Aug 26, 2011, 08:01 PM
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When I saw those nice tools, the first thing I thought was: where is the back-up structure"?

A spar or eggcrate to set the tool onto is a great was to stabilize the tool for only a bit of time/$. I would hate to damage a tool or have it prematurely warp.

Take a look at Burnham composites and how they do it and then copy with wood, pvd rain gutter down spout wrapped in fiberglass cloth or whatever has a SIMILAR expansion rate as the tool.

Scott
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Old Aug 26, 2011, 09:14 PM
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You kinda caught me in the middle of something Scott. lol
The fuse mould won't warp anytime soon. It's almost 1/4" thick and I've already driven my truck over one of the sections with no damage or warp.

This wing mould is an experiment. I am attempting to push the limits of what I've seen done to date in this hobby. I've embedded aluminum infusion channels at acute angles in two planes to add rigidity while bringing the cost down to something that your average highschool kid with a job can manage. It's always been a pet peeve of mine that the cost of tools is prohibitive to those that we should be doing our best to get involved rather than letting our full grown egos justify telling some kid that it could cost $1,000 in just glass and resin to make a tool before he even has an airplane.

Yes, I know all about sub-structures and I won't know what's needed here until I get the plug out of it in the end. My hope is that the perimeter flange and resin infusion channels will be adequate. A perimeter flange is a very powerful tool for adding rigidity. Don't forget that I'm using epoxy that has virtually no appreciable shrinkage over the kind of distances we're dealing with here. If I'd used a polyester gel coat or laminating resin there would most definately have been a frame from the get go.

I've never been one to follow Scott. :-D Lead or just be another sheople cleaning up the shrubby grass left by those that came before. That's why we have ARF's built by little chinese girls who are forced to move to cities without their parents at the age of ten to work in rat infested model airplane factories while we all pretend it would be happening even if it wasn't for our sloth. I don't do Monkey see, Monkey do: I try my best to use more than just my opposable thumbs.

Oops, I get up on my soapbox without even realizing it sometimes....lol

For anyone who's wondering what the hold up is on my templates, I've just had some unexpected house guests leave, so I should be back at it here shortly.
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