Just wanted to let people know of a corrosion issue I have with a Streamlined aluminum extension right where the SS screws contact the aluminum (see pics). Treated with STABIL corrosion control and that stopped more white oxidized aluminum from forming. Always used in salt water and always washed with fresh water after each session. I wrapped the SS screws with 6-7 wraps of teflon tape. Have a newer Streamlined extension that I did the same for and no corrosion so far.

Use duralac its a good compound for mixed metals in marine applications.


Wipe off any access , it can stain surfaces.

Ant-man said..
Yep I had a similar problem. I still think they are the makers of the best hardware though. The fix for me was to go to their carbon extension, costs a fair bit but so compact around the pulleys and so easy to downhaul.

The makers of the best hardware? Really? If you compare the build quality between the 2 photos.....well I don't think there is a comparison. That streamlined looks like it was put together in someone's back shed....badly. I've had my Chinook aly for several seasons and it's still as strong as the day I bought it with no signs of corrosion (and I've never rinsed it after a session). I've no desire to go carbon as I've heard (and seen) too many breakages, especially in the surf. Happy to add a couple of hundred grams of weight for piece of mind. Also their single piece euro pin base is the best Ive found. Just need to replace the tendon occasionally as with all bases. Probably the best windsurfing investment I've made and no i don't work for Chinook nor am I sponsored by them....

Seems a warranty issue

How old? Looks very well used.

Its about 5 yrs old always used in saltwater, always rinsed after use. I still use it for my 8.0 sail and 460 mast, but I can also rig the 8.0 on my 490 and use my other shorter extension. I think it is still strong enough to use, since I caught it in time and stopped the corrosion.

I looked at Chinook, but I wanted the pulleys to be turned 90 degrees so they aligned with the pulleys on my Aerotech Freespeed sails w/o crossing lines, also the Chinook two bolt base was all plastic while the Streamlined has a metal plate. Did not feel comfortable with only plastic holding the mast to the board

AUS3333 said..
Use duralac its a good compound for mixed metals in marine applications.


Wipe off any access , it can stain surfaces.

Okay, thanks

Muppet said..

Ant-man said..
Yep I had a similar problem. I still think they are the makers of the best hardware though. The fix for me was to go to their carbon extension, costs a fair bit but so compact around the pulleys and so easy to downhaul.

The makers of the best hardware? Really? If you compare the build quality between the 2 photos.....well I don't think there is a comparison. That streamlined looks like it was put together in someone's back shed....badly. I've had my Chinook aly for several seasons and it's still as strong as the day I bought it with no signs of corrosion (and I've never rinsed it after a session). I've no desire to go carbon as I've heard (and seen) too many breakages, especially in the surf. Happy to add a couple of hundred grams of weight for piece of mind. Also their single piece euro pin base is the best Ive found. Just need to replace the tendon occasionally as with all bases. Probably the best windsurfing investment I've made and no i don't work for Chinook nor am I sponsored by them....

Have you owned one Muppet? If not don't judge. I'm not sure how you can judge build quality from looking at an image on a screen. There is a reason they are a niche product, the don't mass produce, they specialise. Can you completely de-construct your entire extension to service it?
Check their website, brilliant boom heads and extensions.
To answer the obvious question, yes I've owned a Chinook extension.

Sandman1221 said..
Its about 5 yrs old

what age do you think is a reasonable life for products used in seawater?

My newer 30 cm Streamlined extension is two years old and had no galvanic corrosion before I taped the screw threads, and has not corroded since, and I use it 90% of the time and always in saltwater. Now I did disassemble the 46 cm extension (that has the galvanic corrosion) one time to clean out sand, maybe that disrupted a corrosion resistance coating on the screws?

Imax1 said..
It should be law , just buy a chinook. Replace tendon every year .
Ive had mine for over five years , use it all the time , never wash it even when it's covered with sand and still looks and works great. I don't think it will ever die.
When I restarted sailing again , seven years ago I had a new Gaastra ext and the hole wore out and cracked within a year , got a replacement and the same thing happened again . Then went to NP and because of that tiny crappy little button that got stuck with sand every time , even after washing , even when there was no sand , had to let it go .
Chinooks work covered with sand . They are like a cat , the more you abuse them , the more they love you .

Chinook pulleys are in the wrong orientation for my sails, one reason I got the Streamlined, other than the minor galvanic corrosion on the older 46 cm ext., which has stopped by taping threads and use of Stabil, I have no complaints. And have never replaced a tendon, checked the tendon on the 5-yr old ext. and it had no cracks, and it is hot to warm year round here. If you need to replace tendon every year, you are buying the equivalent of a new ext. over time.

Sandman1221 said.. And have never replaced a tendon, checked the tendon on the 5-yr old ext. and it had no cracks.

The material itself ages, you don't need cracks. It's a bad way to save $18.

As for the pulley orientation, the man himself explains. Easy peasy but don't ask me to do it from the port side of the sail. I'm totally unable on that side.

I think the ext. SS screw heads were holding saltwater between them and the aluminum during my sessions allowing electrolysis to occur. Taped screws with teflon tape, used nylon washers to separate the two metals, and sprayed everything with Boeshield T-9 corrosion protection which leaves a waterproof layer of wax. Will see how that works. The newer ext. (on right) had minor surface corrosion under the screw heads, see pics. Second pic shows reassembled ext. with SS washers and black nylon washers.

Bottom line, whoever designed this should have known the two dissimilar metals needed to be separated by a nylon washer. Glad I caught it early on the newer extension.

Paducah said..

As for the pulley orientation, the man himself explains. Easy peasy but don't ask me to do it from the port side of the sail. I'm totally unable on that side.

If I can do it port and stbd with my profound mental problems and intelligence deficit then anyone can.

Ant-man said..
Have you owned one Muppet? If not don't judge. I'm not sure how you can judge build quality from looking at an image on a screen. There is a reason they are a niche product, the don't mass produce, they specialise. Can you completely de-construct your entire extension to service it?
Check their website, brilliant boom heads and extensions.
To answer the obvious question, yes I've owned a Chinook extension.

Are you kidding!

One can certainly comment on quality, based on the materials, pictures and comments that have been provided!

And you don't need to 'deconstruct' it if it never needs 'servicing' . Your comments sound a little shrill.