[interpol]

Here is the process I was thinking; start off with a piece of foam and you pretty much carve out the shape you want and fiberglass over it to get the form and then cut around the sides to get the nice squared off shape and drill the holes for the tabs, maybe using two layers of fiberglass placing the second after the first has dried for a nice strong material. Before using the fiberglass I would try coating the foam with parafin wax so the mold might be reusable.

Has anyone done this? How hard is it to do? Would the wax thing work? Any tricks or tips before I try it? (I am not trying to reproduce an existing fairing I am trying to make an entirely new design for the tail.)

 

[BikePilot]

Chepla would probably know:thumbup

 

[pmmonster]

Chepla would probably know:thumbup

You might have better luck with Chelapa rather than Chepla

 

[TLs/r]

Here is the process I was thinking; start off with a piece of foam and you pretty much carve out the shape you want and fiberglass over it to get the form and then cut around the sides to get the nice squared off shape and drill the holes for the tabs, maybe using two layers of fiberglass placing the second after the first has dried for a nice strong material. Before using the fiberglass I would try coating the foam with parafin wax so the mold might be reusable.

Has anyone done this? How hard is it to do? Would the wax thing work? Any tricks or tips before I try it? (I am not trying to reproduce an existing fairing I am trying to make an entirely new design for the tail.)

Hey Interpol, did you ever procede with this idea? I was thinking the same thing, did a search and found this thread. Unfortunately no real responses. Any luck?

 

[interpol]

no i haven't done it yet though chelapa sent me some good stuff. i think chelapa vacuum bags - not really sure (just google vacuum bag). i have the foam ready was going to start cutting this weekend. i will take photos and post progress.

 

[interpol]

TLS/R: this weekend I only got around to making a wire foam cutter, it costs about 8$ to make a small hand held one - lots of info on the net. Here's how I made mine - I bought a cheese slicer (the one with the wire on a handle) 3$, a 450mA 12.6v transformer from radio shack 5$ (go with the 1.2A to avoid having trouble with the wire not heating up enough), and an .1 E string from my guitar, I had something to plugin to the wall - I used my laptop adapter and put copper wiring I borrowed from work in the ends and the other ends to the transformer winding, I first tried with a 20W 20ohm resistor in series with my cheese slicer which didn't heat it up enough with the stock wire in place. I removed the resistor and it was hot enough to cut but way too slowly, so I replaced with the E string and it is still a little too cool and it melted the plastic on the cheese slicer so here is how I suggest making one. A 1.2A 12.6v transformer through to a wire cheese slicer which is made of metal and doesn't conduct. This way you don't have to mess around with trying to keep a guitar string tight in the slicer and it will get plenty hot.

 

[TLs/r]

Wow! I've seen those before but never even thought of making one. I was thinking more along the lines of a sanding block. If all goes well maybe you can post up some pics. Good luck and keep the info coming. :thumbup

 

[interpol]

i get most electronics stuff for free from work and i was thinking about it you probably don't need 1.2A running through it to make it that hot about 700-900mA should be enough - I remember reading somewhere that about 1W of power per inch but that was with resistive wire - our load is entirely on the transformer. The 1.2A is like a dollar more, to get within 700-900mA you'll need a resistor. I=E/R .8=12/15 will give you 800mA so 13ohms(.92A) to 17ohms(.7A) will give keep you within range... just afterthoughts I haven't tested any of it yet.

 

[TLs/r]

i get most electronics stuff for free from work and i was thinking about it you probably don't need 1.2A running through it to make it that hot about 700-900mA should be enough - I remember reading somewhere that about 1W of power per inch but that was with resistive wire - our load is entirely on the transformer. The 1.2A is like a dollar more, to get within 700-900mA you'll need a resistor. I=E/R .8=12/15 will give you 800mA so 13ohms(.92A) to 17ohms(.7A) will give keep you within range... just afterthoughts I haven't tested any of it yet.

Hmmmm, Yeeeaaahhh...... Thats what I was thinking :confused ...............not!
I totally respect your knowledge to understand this but I think I will just let you build it then buy one from you. :laugh :hail

I'll just be going to the garage to sand my foam with a rock now.... :no

 

[interpol]

Hmmmm, Yeeeaaahhh...... Thats what I was thinking :confused ...............not!
I totally respect your knowledge to understand this but I think I will just let you build it then buy one from you. :laugh :hail

I'll just be going to the garage to sand my foam with a rock now.... :no

lol. i'll let ya know how it turns out, we have another long weekend coming because they are holding the Marine Corps ball a week later than the bday down here for some reason :O

 

[chucks_net]

For cutting plastics I usually use a hotknife. I take a 1" piece of radio antenna and slide it over the tip of my soldering iron, then squish the antenna tube extending out past the tip flat like a knife. Or you could buy one of these

For fiberglass body work (back yard style) I use a drywall open mesh sandpaper -it really takes away material fast. Here is a pic of the sandpaper

 

[interpol]

that is a good idea for the cutter chuck, i'll try that one out thanks. i dunno if that was in reply to the cutter i've made but the one i am working on is for foam, i think the soldering iron might be a little too hot for foam and melt to much of it away.

 

[chucks_net]

that is a good idea for the cutter chuck, i'll try that one out thanks. i dunno if that was in reply to the cutter i've made but the one i am working on is for foam, i think the soldering iron might be a little too hot for foam and melt to much of it away.

Everyone I know who cuts foam uses an electric knife.

 

[interpol]

oh, okay. i tried out my soldering iron but it melts away the foam in a lot bigger area than what it touches.

 

[interpol]

okay i used nuts and big washers to dissipate heat and then did what chuck said cause it is easier and works. thanks chuck.

 

[Mr. DOBALINA]

Everyone I know who cuts foam uses an electric knife.

That's pretty cool Chuck!




I'm decidedly old school so me does it the old fashion way.




Kind of like this:

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:laugh

.