My Wood & Foam Bridi UFO Build
01-22-2012, 08:29 PM
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RE: My Wood & Foam Bridi UFO Build
ORIGINAL: speedracerntrixie
After this cures you can split it along the top into two halves. Mold up the 2 halves seperatly. To join the two halves just tape together on the outside and seam with a 1/2" strip of cloth on the inside. You would end up with a lighter part and less work.
After this cures you can split it along the top into two halves. Mold up the 2 halves seperatly. To join the two halves just tape together on the outside and seam with a 1/2" strip of cloth on the inside. You would end up with a lighter part and less work.
Here's two links from CST Sales
http://www.cstsales.com/fiberglass_mold_instr.html
http://www.cstsales.com/tutorials/fiberglass_mold.pdf
Bryan
01-23-2012, 03:43 AM
#577
RE: My Wood & Foam Bridi UFO Build
I bet Atlanta 60 would confirm that. He astounded me when I saw his mold work in person. I had no idea how that worked until I saw his project.
01-23-2012, 06:31 PM
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RE: My Wood & Foam Bridi UFO Build
I don't really see the point of going through all the time and effort to make a two part cavity mold just to produce one canopy. This one off, lost foam method will be much faster as long as I don't screw up the glassing part and have to start over! [X(]
David,
Yes, I'm using West System epoxy. It's nice stuff to work with.
RG [8D]
David,
Yes, I'm using West System epoxy. It's nice stuff to work with.
RG [8D]
01-29-2012, 08:56 AM
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RE: My Wood & Foam Bridi UFO Build
Brian,
I haven't decided yet how I'm going to mount the air tank. I've been thinking about it though!
The quick and dirty way to do it would be to just tack it in place with a couple dobs of clear silicone(RTV). I did it that way years ago for a set of homemade air cylinders that I made for a set of Goldberg retracts that went into a Dirty Birdy .40. I used a WD-40 can for the tank. The RTV worked well, but this time I want it to be easily removable.
Right now I'm leaning towards some sort of cradle for the tank and hold it in place with a couple of small zip ties. The trick here would be to make the cradle so it doesn't interfere with the installation and removal of the fuel tank. Still thinking about it!
I have some time before the tank goes in to figure it all out.
RG
I haven't decided yet how I'm going to mount the air tank. I've been thinking about it though!
The quick and dirty way to do it would be to just tack it in place with a couple dobs of clear silicone(RTV). I did it that way years ago for a set of homemade air cylinders that I made for a set of Goldberg retracts that went into a Dirty Birdy .40. I used a WD-40 can for the tank. The RTV worked well, but this time I want it to be easily removable.
Right now I'm leaning towards some sort of cradle for the tank and hold it in place with a couple of small zip ties. The trick here would be to make the cradle so it doesn't interfere with the installation and removal of the fuel tank. Still thinking about it!
I have some time before the tank goes in to figure it all out.
RG
01-29-2012, 10:16 AM
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RE: My Wood & Foam Bridi UFO Build
Yesterday I got started laying up the glass cloth over the canopy plug.
After applying two coats of epoxy over the plug it was sanded smooth and I applied four coats of Carnauba Paste wax.
In a previous post Don mentioned that he used a layer each of 6 & 3.7 oz cloth to do his canopy. I don't have any 3.7 oz cloth so I'll be going with one layer each of 6, 2 and 1.5 oz. cloth. I was hoping to lay up all three layers at one time time, but that didn't work out. I had some issues with the 6 oz cloth not laying down into the side tucks of the canopy. I had a feeling these tucks might end up being a problem!
On the left side of the canopy I had no problems with the tuck, but for some reason on the right side the cloth kept pulling away from the plug. I think I might have pulled the cloth on that side in a funny direction which affected how well it lays down. I ended up having to continuously work the cloth down until the epoxy tacked up enough to hold it in place. With the slower West System hardener that took about 3 hours! [X(]
This morning I trimmed away some of the excess 6 oz. cloth, sanded the glass a little and applied the layer of 2 oz. The 2 oz. cloth has a more dense weave than the 6 oz. and it took a little more effort to work it down over the compound curves at the front of the canopy. I was more careful this time regarding the direction of the weave and had no problems with the cloth laying down in the tucks. I'll let this cure overnight and then apply the last 1.5 oz. layer.
I think, in the end, having to lay up each layer of cloth separately will probably be a good thing and will result in a better part. At least that's what I'm hoping!
RG [8D]
After applying two coats of epoxy over the plug it was sanded smooth and I applied four coats of Carnauba Paste wax.
In a previous post Don mentioned that he used a layer each of 6 & 3.7 oz cloth to do his canopy. I don't have any 3.7 oz cloth so I'll be going with one layer each of 6, 2 and 1.5 oz. cloth. I was hoping to lay up all three layers at one time time, but that didn't work out. I had some issues with the 6 oz cloth not laying down into the side tucks of the canopy. I had a feeling these tucks might end up being a problem!
On the left side of the canopy I had no problems with the tuck, but for some reason on the right side the cloth kept pulling away from the plug. I think I might have pulled the cloth on that side in a funny direction which affected how well it lays down. I ended up having to continuously work the cloth down until the epoxy tacked up enough to hold it in place. With the slower West System hardener that took about 3 hours! [X(]
This morning I trimmed away some of the excess 6 oz. cloth, sanded the glass a little and applied the layer of 2 oz. The 2 oz. cloth has a more dense weave than the 6 oz. and it took a little more effort to work it down over the compound curves at the front of the canopy. I was more careful this time regarding the direction of the weave and had no problems with the cloth laying down in the tucks. I'll let this cure overnight and then apply the last 1.5 oz. layer.
I think, in the end, having to lay up each layer of cloth separately will probably be a good thing and will result in a better part. At least that's what I'm hoping!
RG [8D]
01-29-2012, 01:09 PM
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RE: My Wood & Foam Bridi UFO Build
ORIGINAL: R_G
In a previous post Don mentioned that he used a layer each of 6 & 3.7 oz cloth to do his canopy. I don't have any 3.7 oz cloth so I'll be going with one layer each of 6, 2 and 1.5 oz. cloth. I was hoping to lay up all three layers at one time time, but that didn't work out. I had some issues with the 6 oz cloth not laying down into the side tucks of the canopy. I had a feeling these tucks might end up being a problem!
On the left side of the canopy I had no problems with the tuck, but for some reason on the right side the cloth kept pulling away from the plug. I think I might have pulled the cloth on that side in a funny direction which affected how well it lays down. I ended up having to continuously work the cloth down until the epoxy tacked up enough to hold it in place. With the slower West System hardener that took about 3 hours! [X(]
In a previous post Don mentioned that he used a layer each of 6 & 3.7 oz cloth to do his canopy. I don't have any 3.7 oz cloth so I'll be going with one layer each of 6, 2 and 1.5 oz. cloth. I was hoping to lay up all three layers at one time time, but that didn't work out. I had some issues with the 6 oz cloth not laying down into the side tucks of the canopy. I had a feeling these tucks might end up being a problem!
On the left side of the canopy I had no problems with the tuck, but for some reason on the right side the cloth kept pulling away from the plug. I think I might have pulled the cloth on that side in a funny direction which affected how well it lays down. I ended up having to continuously work the cloth down until the epoxy tacked up enough to hold it in place. With the slower West System hardener that took about 3 hours! [X(]
Here's a tip. If you heat up the epoxy it will cure like a fast hardener. I'vedone this withWest Systems epoxy three different waysand it works great.
First way is to heat up the mixed batch in a microwave for 5 to 8 seconds. My microwave is 1500watts so you'll need to adjust for the power of your microwave. Any long than 8 seconds in my microwave and I have maybe a minute or two depending on the size of the batch (1 to 2 ounces) and it's very hot and can melt things that are plastic.After heating I mix again and then just pout it over the fiberglass and spread it as fast as I can. If it's blazin hot when it comes out of the microwave it will go off in less than a minute.
Next you could use your heat gun for monokote or a blow dryer for hair and heat the epoxy until just warm to the touch. I like this method cause it's easy to control the heat.
The last way is to cure the epoxy under an incandesant light bulb. The higher strength and higher heat tolerant epoxies use heat over a peroid of time to add strength or heat tolerance to the resin.
Looks great! Excellant build thread by the way.
01-29-2012, 02:09 PM
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RE: My Wood & Foam Bridi UFO Build
ORIGINAL: Roguedog
Wow! For all that time you could have made a mold for the canopy.
Wow! For all that time you could have made a mold for the canopy.
ORIGINAL: Roguedog
Here's a tip. If you heat up the epoxy it will cure like a fast hardener. I've done this with West Systems epoxy three different ways and it works great.
First way is to heat up the mixed batch in a microwave for 5 to 8 seconds. My microwave is 1500watts so you'll need to adjust for the power of your microwave. Any long than 8 seconds in my microwave and I have maybe a minute or two depending on the size of the batch (1 to 2 ounces) and it's very hot and can melt things that are plastic. After heating I mix again and then just pout it over the fiberglass and spread it as fast as I can. If it's blazin hot when it comes out of the microwave it will go off in less than a minute.
Next you could use your heat gun for monocoat or a blow dryer for hair and heat the epoxy until just warm to the touch. I like this method cause it's easy to control the heat.
The last way is to cure the epoxy under an incandesant light bulb. The higher strength and higher heat tolerant epoxies use heat over a peroid of time to add strength or heat tolerance to the resin.
Looks great! Excellant build thread by the way.
Here's a tip. If you heat up the epoxy it will cure like a fast hardener. I've done this with West Systems epoxy three different ways and it works great.
First way is to heat up the mixed batch in a microwave for 5 to 8 seconds. My microwave is 1500watts so you'll need to adjust for the power of your microwave. Any long than 8 seconds in my microwave and I have maybe a minute or two depending on the size of the batch (1 to 2 ounces) and it's very hot and can melt things that are plastic. After heating I mix again and then just pout it over the fiberglass and spread it as fast as I can. If it's blazin hot when it comes out of the microwave it will go off in less than a minute.
Next you could use your heat gun for monocoat or a blow dryer for hair and heat the epoxy until just warm to the touch. I like this method cause it's easy to control the heat.
The last way is to cure the epoxy under an incandesant light bulb. The higher strength and higher heat tolerant epoxies use heat over a peroid of time to add strength or heat tolerance to the resin.
Looks great! Excellant build thread by the way.
Thanks!
RG
01-31-2012, 07:07 PM
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RE: My Wood & Foam Bridi UFO Build
Took some time today after work to apply the last layer of 1.5 oz. cloth. I'll let it cure until the weekend and then trim & "gut" it! I'm curious to see what this thing weighs when it's done! 
RG [8D]
RG [8D]
02-04-2012, 02:24 PM
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RE: My Wood & Foam Bridi UFO Build
This morning I finished up the canopy by first trimming & sanding the excess fiberglass flush with the base of the plug. Then the 1/64" plywood base was removed by cutting most of it away with an X-acto knife and peeling out what was left. The majority of the foam was removed with a hot wire and the 1/32" plywood formers were pulled out carefully with needle nose pliers. What was left of the foam was melted away with acetone. Up to this point things were moving right along, then I ran into some trouble!
The four coats of spackle I applied to the foam to smooth it out were still in the canopy. Even though I applied two coats of epoxy over the spackle to seal it and four coats of paste wax to aid in it's removal, the stuff just did not want to come out easily! Man. what a P.I.T.A. that turned out to be! With the help of a few X-acto knives I chipped away at it for over an hour and a half before I finally got it all removed! [X(]
Once all the spackle was out, the edges and the surface of the canopy were sanded smooth and it was given a bath with warm soapy water to wash away all the fiberglass dust. My new epoxy scale tells me it weighs in at 1.25 oz. I think that's a decent weight considering the size of this canopy.
For my first attempt at molding a glass canopy I think it turned out OK. It's not perfect by any means, but it will do just fine. I'll do better next time.
A few lessons I learned here are:
1. Don't use regular Styrofoam. Cough up the bucks for a sheet of the dense insulation foam.
2. Don't use spackle or epoxy to seal the foam and smooth it out. It's not necessary.
3. Pay attention to the direction of the weave of the glass cloth while applying it.
RG [8D]
The four coats of spackle I applied to the foam to smooth it out were still in the canopy. Even though I applied two coats of epoxy over the spackle to seal it and four coats of paste wax to aid in it's removal, the stuff just did not want to come out easily! Man. what a P.I.T.A. that turned out to be! With the help of a few X-acto knives I chipped away at it for over an hour and a half before I finally got it all removed! [X(]
Once all the spackle was out, the edges and the surface of the canopy were sanded smooth and it was given a bath with warm soapy water to wash away all the fiberglass dust. My new epoxy scale tells me it weighs in at 1.25 oz. I think that's a decent weight considering the size of this canopy.
For my first attempt at molding a glass canopy I think it turned out OK. It's not perfect by any means, but it will do just fine. I'll do better next time.
A few lessons I learned here are:
1. Don't use regular Styrofoam. Cough up the bucks for a sheet of the dense insulation foam.
2. Don't use spackle or epoxy to seal the foam and smooth it out. It's not necessary.
3. Pay attention to the direction of the weave of the glass cloth while applying it.
RG [8D]
02-04-2012, 03:18 PM
#586
RE: My Wood & Foam Bridi UFO Build
<div style="margin: 0in 0in 0pt">
Excellent work on the canopy Ralph!!
</div><div style="margin: 0in 0in 0pt"></div><span style="font-size: 12pt">Now it really is a “UFO” with the canopy in place! 
</span>
Excellent work on the canopy Ralph!!
</div><div style="margin: 0in 0in 0pt"></div><span style="font-size: 12pt">Now it really is a “UFO” with the canopy in place! </span>
02-12-2012, 05:18 PM
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RE: My Wood & Foam Bridi UFO Build
I've been thinking about what to do with the finish on this UFO. The original plan was to go the dope & silkspan route, but I've been wondering if glassing the model might end up being faster. Having never glassed an entire airplane before I thought I'd get my feet wet and give glassing the ailerons and rudder a go.
After completing the job I came to the conclusion that this process is not for me! [X(]
I'll stay with what I know and go with the dope & silkspan.
RG [8D]
After completing the job I came to the conclusion that this process is not for me! [X(]
I'll stay with what I know and go with the dope & silkspan.
RG [8D]
02-18-2012, 10:17 AM
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RE: My Wood & Foam Bridi UFO Build
The canopy has been attached.
I started by applying a piece of self adhesive 120 grit sand paper to the top of the fuselage. The canopy was then sanded to match the fuselage. Next it was taped into position and a line was drawn around it on the fuselage top block.
I mixed up some epoxy and added a bit of Microlight filler to give it a little body. This mixture was applied along the previously drawn canopy outline and the canopy was put in position and held in place with masking tape. The excess epoxy that oozed out was wiped up.
After the epoxy had cure overnight I glassed the canopy to the fuselage using 1.5 ounce cloth. Once the epoxy cured the excess cloth was removed and the edges sanded to a feather edge.
With the canopy attached this model is now an "OFFICIAL" UFO!
RG [8D]
I started by applying a piece of self adhesive 120 grit sand paper to the top of the fuselage. The canopy was then sanded to match the fuselage. Next it was taped into position and a line was drawn around it on the fuselage top block.
I mixed up some epoxy and added a bit of Microlight filler to give it a little body. This mixture was applied along the previously drawn canopy outline and the canopy was put in position and held in place with masking tape. The excess epoxy that oozed out was wiped up.
After the epoxy had cure overnight I glassed the canopy to the fuselage using 1.5 ounce cloth. Once the epoxy cured the excess cloth was removed and the edges sanded to a feather edge.
With the canopy attached this model is now an "OFFICIAL" UFO!
RG [8D]
02-19-2012, 12:53 PM
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RE: My Wood & Foam Bridi UFO Build
Thanks guys!
Getting closer to the silkspan, but there's still a lot of prep work to do before I break out the can of dope. I'm hoping by the time all the prep is done the weather will be more conducive to doping!
RG
Getting closer to the silkspan, but there's still a lot of prep work to do before I break out the can of dope. I'm hoping by the time all the prep is done the weather will be more conducive to doping!
RG
02-23-2012, 06:05 PM
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RE: My Wood & Foam Bridi UFO Build
ORIGINAL: spot171123
I love this build,it's like waitting for my next RC magazine to come in the mail.
come on nice weather!!!!!!!!!
Bruce
I love this build,it's like waitting for my next RC magazine to come in the mail.
come on nice weather!!!!!!!!!
Bruce
Thanks, Bruce!
02-25-2012, 10:09 AM
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RE: My Wood & Foam Bridi UFO Build
The Microlight I used for the wing fillets is great stuff to work with, but it does have a down side. It doesn't handle solvent based paints very well. West System recommends sealing it with epoxy before applying a finish. Since the Microlight is considered to be non-structural I decided to apply a layer of .75 oz. glass cloth for a little added strength instead of just straight epoxy.
RG [8D]
RG [8D]
