603 or Solder

[Gerwin Brommer]

648 forever !
Combined with the "Activator spray" , it becomes even stronger.
I clean my flex with hydrochloric acid from the DIY store.

[Jeff Wohlt]

648 here...over a 700 wire drives and only a handful have let go...not sure if it was install issues or what.

648 works well with SS....some do not.

[sailr]

I use 603 on shafts up to .187 swinging 50mm props at 1600KV 6S with no problems.

[ScarabChris]

Yup, when putting a flex shaft into a stub shaft use silver solder. Clean it up real good first. I used to run large scale gas boats and the properly done silver solder joint never lets go. And we're talking about very torquey high HP gas engines pushing 20+ pound boats.

[graill]

638 is probably the best one to use as its the strongest with the largest gap filling, 648 is the weakest of the 3 mentioned but has a higher temperature capability which is probably no advantage in this situation. The 603 has better oil tolerance than the other 2. Martin.
603 638 648
diam clearance 0.1mm 0.25mm 0.15mm
shear strength 22.5N/mm 25N/mm 13.5N/mm
3260psi 3625psi 1957psi

Your information is wrong Martin, or in your case correct if you are using a part with uncured adhesive. Martin, you will notice the data sheets cure times are not in order. A simple mistake.

Below are the fully cured numbers as i stated before in the previous post, Martin is showing Just assembled non cured numbers for 648 and misread the data sheet.

24 hour cure specs.

Additional info is on the loctite site to include the msds and data sheets on all brands. I suggest you look up your own specs and requirements.

Weakest 603 N/mm 22.5 PSI 3,260 High oil resistance, low heat tolerance, low vibration

Low temp 638 N/mm 25 PSI 3,625 Low oil resistance, low heat, Low vibration, high gap fill

High temp 648 N/mm 25 PSI 3, 625 Low oil resistance, high heat, High vibration, low gap fill

Choose your poison.

We do not need the uncured umbers so i will omit these.

[martin]

Appologies your are correct i copied the wrong numbers on the 648, I put down the 15min cure time & not the 24hour. Martin.