Well the title says it all. I have built 6 gas boats and am finishing up the build of an Aeromarine Avenger. Great company and fantastic boat. Anyway, I was planning on getting her wet this weekend and just had the stuffing tube shape and install to do. While shaping the tube I couldn't get just the right angle of attack into the collet and applied to much pressure. Kinked it! Had a spare and did the same darn thing.

I have another tube on its way and want to make sure I do everything I can to keep this from happening again. So, tonight I made a template out of cardboard in preparation for the shaping of the tube. I was thinking about warming the tube with a hair dryer to make it more plyable. Any other tips and tricks I am missing here??? By the way I did have the flexshaft in the stuffing tube when I kinked both tubes and they are lined with teflon.

I tape up one end, fill the stuffing tube with salt, tap it until the salt is compacted in the tube and then tape up the remaining end & gently bend it over a pumped up bike tyre. On tighter bends I have heated up the tube with a torch to aneal it before bending, this makes it easier to bend also. As you've discovered using the flex cable still allows the tube to kink if too much pressure is applied. The tube filled with salt will be harder to kink, but it can still happen.

I have kinked a few tubes before, once you get the knack of it you'll never bend another one.

Good Luck.

In all honesty, I bend most of my tubes with nothing in it at all. If you are kinking it you are trying to bend too much in one particular angle. Shouldn't be that tight of an angle...maybe engine is at too much of an angle to begin with. I have heated tubes to anneal, that works well too, but not with teflon lined tubes like you have...it will melt the liner. Just go a little bit at a time and make sure you don't have too much angle on the motor. If it's bent enough to kink, it will definitely be a tight spot for the flex anyway.

The angle is not to much. The angle is gradual into the bottom of the hull. I started the bend on the tube too far forward and was tring to bend back to neutral. I think having a template next go around will help. If I heat (just warm) with a hairdryer, would that still melt the teflon liner. Doesn't teflon stand up to a good deal of heat?

It won't do any good to heat it slightly. You will melt that liner...it's very thin. To get the brass to soften, you have to heat it red hot then let it cool. Otherwise you are wasting your time...it will just cost you new tubes! Try the salt/sand tip posted above, that should help you get it done. Also you're template idea is a good one. Good luck.

Just install the flex into the tube and bend it over your knee,ive never kinked a tube yet,i try to use an s bend as it has been proved to have the least friction and drag .Also get rid of the teflon liner,not needed and buy the right size tube and use grease,you need a 5/16" tube.
Mart

I use a product like contained within this link, don't know what specific grade it is because it came from my father years ago.
Looks like lead, soft like lead but MELTS at less than the temp of boiling water !! ( Likely the 117 or 136 product )

See: rds.yahoo.com/_ylt=A0oGkwNIRCF...cts/fusible.htm

Preheat tube & lead product ... Cap one end of tube and fill it up, allow to cool.

Bend away to your hearts content, heat up tube allow lead product to melt and flow out of tube.

GREAT stuff :drinks:

Scott wrote:
Does this work with Teflon lined tubes like he's using though? I think you use Teflon lined tubes also right Scott?

It should, the "So Called" teflon tubes are in most cases actually nylon
Either liner material is unaffected by heat in the 200 degree F or less range.

Best case would be bend tubing PRIOR to the insertion of liner

Wow all that messing about just to bend a stuffing tube i just dont get it? just put the flex in there or fill with salt as has been said and bend it by hand no heating or messing about .
Mart