Flexible ducts

[slownlow]

One of the things that stumped me for a while was fabricating flexible ducts for engine air intake on my last project. I finally tumbled onto this solution after using these applicators many times for their intended use. 

[Ace-Garageguy]

Excellent. Great tip.

What exactly are those?

[Renegade]

Looks like it could be a flexi straw.

[slownlow]

I currently don't have an unused microbrush to photo but hopefully you can visualize one from the 2 used ones in the pic. When new they have a small tuft at the tip for small paint or glue application. They are made of plastic and I use only the serrated section, bent the curve and pinn the ends by way of short lengths of straight pin to the engine and body.

[BigTallDad]

Another approach (although very tedious) is wrap small gauge wire around the threads of a bolt, then wrap that assembly with wet paper. Just before the paper is dry, bend the assembly to the desired contour.

[Ace-Garageguy]

Another approach (although very tedious) is wrap small gauge wire around the threads of a bolt, then wrap that assembly with wet paper. Just before the paper is dry, bend the assembly to the desired contour.

You just inspired this idea...lubricate the threads of a small diameter bolt, heat-shrink it, and screw the bolt out.

Worth a try, anyway.

[peteski]

I had a similar problem on my 1:43 289 Cobra. I made mine by wrapping a bare copper wire over a brass rod. I then removed the "spring" off the rod ( I had to loosen the coils slightly).  Then I dipped the "spring" into a thinned black Plasti-Dip liquid (the stuff used to dip tool handles).  It took some experimenting with how much to thin the plastic dip so it works just right. I let it dry and dipped it again, probably for the total of 3 times to build up the thickness.  That resulted in a nice flexible ducting.  It is fairly small diameter (remember, this is 1:43 scale).

 

Edited September 20, 2017 by peteski

[BigTallDad]

Very nice looking ducts!

If you wrap the wire around a threaded bolt, the threads will make the spacing even. After wrapping the wire, unscrew the bolt and proceed as usual.

[Deathgoblin]

I have heard of using the thin tape used for wrapping plumbing threads for ducts.  Same process of wrapping wire around a bolt/screw, then wrapping the tape around that.

[BigTallDad]

I have heard of using the thin tape used for wrapping plumbing threads for ducts.  Same process of wrapping wire around a bolt/screw, then wrapping the tape around that.

How do you glue/paint the tape? Most plumbing tape is Teflon, and not many things stick to Teflon.

[Deathgoblin]

How do you glue/paint the tape? Most plumbing tape is Teflon, and not many things stick to Teflon.

True!!   I guess that wasn't a good idea.  Sorry.

[peteski]

Very nice looking ducts!

If you wrap the wire around a threaded bolt, the threads will make the spacing even. After wrapping the wire, unscrew the bolt and proceed as usual.

Thanks!

The threaded bolt works, but in my example I used thick enough wire that I wrapped each turn tightly touching the previous turn. It sort of looked like one of the thick guitar strings before I dipped it in the Plasti-Dip.

[HGLOVAL]

Take a metal rod or dowel the same diameter as the ducts.  Wrap small gage wire around it.  Then wrap Teflon tape around the wire.  Coat it with diluted white glue and paint.  Cut to length.  There's a tutorial on Italianhorses.net on how to do this.

[Art Anderson]

Looks like it could be a flexi straw.

Flexible plastic drinking straws have one serious drawback:  They are made from a very low grade of whatever plastic, and as such, tend to crumble into little flakes of plastic over time.

Art

[10thumbs]

The straws look great, hopefully they last a while.

Great looking ducts shown.  Peter's look fantastic!

A year or so ago I tried this method on a 1:25 truck:

Since the whole truck (except body) was brass and nickel, I wanted metal ducts too.  These are aluminum tubes, with an indentation around and a wire wrapped into the cut grooves.  Looks fairly believable on a finished model.

 

 

Edited October 17, 2017 by 10thumbs

[ChrisBcritter]

Then I dipped the "spring" into a thinned black Plasti-Dip liquid (the stuff used to dip tool handles).  It took some experimenting with how much to thin the plastic dip so it works just right.

Pete, what did you use to thin the Plasti-Dip?

[peteski]

Pete, what did you use to thin the Plasti-Dip?

I looked at the ingredients list on the Plasti-Dip can and used some of those chemicals. IIRC, it was Naphtha and acetone.  Then I poured the thinned stuff into a small diameter glass test tube (about 2" long) and I dipped my metal spring in it multiple times (letting the previous coat dry).  It took some experimenting for arriving at the right viscosity for dipping.

 

[Brutalform]

I’ve used flexi straws painted with Tamiya Rubber Black and have had great results.

[Psychographic]

I use flexible straws for filling molds on certain resin projects. One day I decided to carefully cut the straw after the resin hardened, it made a fairly nice looking duct.

[Casey]

On 10/14/2017 at 9:36 AM, HGLOVAL said:

 There's a tutorial on Italianhorses.net on how to do this.

http://italianhorses.net/Tutorials/FlexHose/flexhose.htm

 

[MeatMan]

On 9/24/2017 at 9:25 PM, Deathgoblin said:

How do you glue/paint the tape? Most plumbing tape is Teflon, and not many things stick to Teflon.

True!!   I guess that wasn't a good idea.  Sorry.

I've used the teflon method and it works, and paints. Its been a while but I'll try to dig up pics.

[Roncla]

I followed the Italianhorses tutorial when I built this contraption. i just brushed white glue over the teflon once I'd made the hose and then painted as usual.

 

 

[Ben]

Take a small spring, slide a piece of heat shrink for wires over it then heat it until it shrinks to the desired look you’re going for.

[Deathgoblin]

The truck looks awesome!