Trampoline attachment buttons

[DotDun]

Originally Posted by Stumble

I deal with galvanic issues all the time, anodizing has little to no effect on galvanic corrosion. If you want I can refer you to the corrosion engineer I work with on offshore parts you are welcome to call his firm and pay for his opinion. Or you can read almost anything from credible engineering sources about galvanic corrosion. If you would like to cover this in detail free free to start a thread on it.

Anodizing World: Corrosion between anodized aluminum and steel

From the supplied link:

It is unusual to see galvanic corrosion on aluminum in contact with stainless steel (passive). In contrast contact between copper, bronze, brass and different kinds of steel alloys (passive and active) and aluminum can cause severe corrosion so it is advisable to provide insulation between the two metals.

The reason for the confusion of the galvanic corrosion between aluminum and steel is that stainless steel can be found as passive or active, and if the environment contains chloride. This will change the corrosion effect on aluminum substantially. Generally, the closer one metal is to another in the series, the more compatible they will be, i.e., the galvanic effects will be minimal. Conversely, the farther one metal is from another, the greater the corrosion will be.

Conclusion: It depends!

As Cotemar has stated, the corrosion that is causing us the most pain is NOT where the SS contacts the aluminum. Hence, the chances that anodizing will solve our current issue is quite high. We'll deal with the continued corrosion between the anodized button and SS mounting screw. We'll search for 'passive' SS screws!

[colemj]

The corrosion shown in the picture is not galvanic - it is poultice corrosion caused by continual contact with wet material (tramp line) not allowing oxygen to react with the aluminum. While anodizing will slow this process, it will still happen over time - particularly since the rubbing of the line will slowly remove the thin anodized layer.

I would be a bit wary about plastic buttons in tropic sun. If they were nylon, teflon or delrin (or similar HMW polyethylene), that would be much better.

Mark

[Stumble]

Mark,

I am pretty sure the ones from Corsair are actually HMPE but to be honest I'm not sure. The ones I have are from a 5 year old Florida boat and still look fine so your right they aren't likely plastic.

[muskoka]

What about using a 15mm plain acetal sheave which costs about $1.20. If needed you could put a 25mm stainless steel washer on top to retain the rope. The plastic will last a lot longer than the aluminum buttons and it's half the price.

APS - Holt Allen Replacement Sheaves

Cheers

[GRIT]

I must have missed a post somewhere, are you selling these netnobs? If so, how much? What is the spacing between nobs? I'll have to figure out how many to buy, but that's a great looking product.

Nice job, they look great. Please contact me with pricing at: Svquintana at gmail dot com

Cheers.
Paul.

[Kiwikat]

Originally Posted by Cotemar

Don't have to. I can have him send them to you. Have 150 of them spoken for so far.

Hi Cotemar, are there any more available. I need 45 for my Bahia.

Cheers
Lisa

[Dragon Lady]

Thank you everyone, I've just emailed Multi hull nets for a price.

[Cotemar]

Originally Posted by Kiwikat

Hi Cotemar, are there any more available. I need 45 for my Bahia.

Cheers
Lisa

Yes, No Worries. PM sent

[mikefp60]

They call them lacing posts. Just ordered 30 of them. 6 1/2 bucks each.


Sunrise Yacht Products
6544 44th St N Unit 1205
Pinellas Park FL 33781
Mailto; info@multihullnets.com
Website: http://www.multihullnets.com/Product/ProductHdwr.aspx
Phone; 727 526 9288 Fax; 727 528 0351

[Cotemar]

Originally Posted by mikefp60

They call them lacing posts. Just ordered 30 of them. 6 1/2 bucks each.

Sunrise Yacht Products
6544 44th St N Unit 1205
Pinellas Park FL 33781
Mailto; info@multihullnets.com
Website: http://www.multihullnets.com/Product/ProductHdwr.aspx
Phone; 727 526 9288 Fax; 727 528 0351

How many do you use on a FP Eleuthera 60 ?

[Kiwikat]

Thanks Cotemar,

We are actually just today, about to fit our brand new trampoline which we had made and shipped out by Sunrise Yacht products. Our old tramp is falling apart and we have an important charity regatta to do on Friday with lots of guests. We will just use the existing knobs for now but will get the new ones at a later date.

Cheers
Lisa