Seat Pan

[MrSteve]

A little background first, O.K.?

Alrtighty then,
the Sofrider arrived in it's crate in Spring, about a few years back.
Summer was, and is, a humid and hot time to ride here in the
Southeast U.S.
Soon, the black seat cover was sporting white, salty sweat stains.

Time for a wash!

I don't know about you guys, but it took me the better part of an hour
to take the cover off of the foam pad, the big one.
It was a warm day, the foam was pretty pliable, but the cover is
not designed to be easily serviced.

I never did that again: just kept the bike wiped clean and slapped the seat cover
free of salt crystals every now and then.
The risk of tearing the seat cover was simply too great.

Now, here it is a few years later (almost).
I took the seat cover/seat foam assemblies off the bike's alloy seat pans
for a thorough cleaning...and saw the usual scuff-marks in the finish of the
seat pans.
Looking closer...I noticed that there is actual pitting of the alloy, where the seat cover
sits firmly against the seat pan.
Also, the mild steel nuts that secure the alloy bottle gages to the seat pan are quite
corroded: rusty.

You've noted my nom-de-plume?
"Yakmurph"?
One o' my other passions is sea kayaking: I'm familiar with galvanic corrosion.

My salty sweat has been completing a circuit between the alloy seat pan, the mild
steel bolts and the damp seat cover.
On my bike, the sacrificial anode is the seat pan.

So, for me, the solution is a FRP seat pan.
I'm using my bike's seat as a plug-mold....



-Steve

 

[Mark B]

:shock: :shock: Plus, it's a$$ sweat, which has to be like, twice as corrosive! :shock: :shock:

Mark

 

[MrSteve]

Mark B wrote: :shock: :shock: Plus, it's a$$ sweat, which has to be like, twice as corrosive! :shock: :shock:

Mark

:? Ye ain't jest a-whisslin' Dixie! :shock:

-Steve
:lol:

 

[Peder Torgersen]

yakmurph wrote: A little background first, O.K.?

Alrtighty then,
the Sofrider arrived in it's crate in Spring, about a few years back.
Summer was, and is, a humid and hot time to ride here in the
Southeast U.S.
Soon, the black seat cover was sporting white, salty sweat stains.

Time for a wash!

I don't know about you guys, but it took me the better part of an hour
to take the cover off of the foam pad, the big one.
It was a warm day, the foam was pretty pliable, but the cover is
not designed to be easily serviced.

I never did that again: just kept the bike wiped clean and slapped the seat cover
free of salt crystals every now and then.
The risk of tearing the seat cover was simply too great.

Now, here it is a few years later (almost).
I took the seat cover/seat foam assemblies off the bike's alloy seat pans
for a thorough cleaning...and saw the usual scuff-marks in the finish of the
seat pans.
Looking closer...I noticed that there is actual pitting of the alloy, where the seat cover
sits firmly against the seat pan.
Also, the mild steel nuts that secure the alloy bottle gages to the seat pan are quite
corroded: rusty.

You've noted my nom-de-plume?
"Yakmurph"?
One o' my other passions is sea kayaking: I'm familiar with galvanic corrosion.

My salty sweat has been completing a circuit between the alloy seat pan, the mild
steel bolts and the damp seat cover.
On my bike, the sacrificial anode is the seat pan.

So, for me, the solution is a FRP seat pan.
I'm using my bike's seat as a plug-mold....



-Steve

Aluminum if it’s in contact with stainless steel there will be an anode and you will get corrosion.
You can stop it by using a cheap solution a plastic washer or a washer that is made of a material that will isolate so the two materials aren’t in contact with each other. Stainless steel is not stainless if it’s in contact with ordinary steel so using plastic washers is often used in industrial structures. It’s also used when aluminum is bolted to stainless steel and ordinary steel.
You can paint on aluminum but it needs a special primer first. If you paint without the special primer the paint will come off soon.

Peder

 

[trapdoor2]

One of the things we used to prevent such corrosion (back in my days as a Gulf Coast helicopter mechanic), was to simply apply a layer of clear-plastic tape to the area. We had the stuff in very wide rolls (like 6-8") for big areas. It is flexible enough to conform to compound curves and you can just overlap where you need more coverage. Judicious application of heat from a hair dryer will help a lot with the curves.

Glad you brought this up, 'cause I sweat like a....well, like a large, fat, human. I will do exactly the above with my seatpan/back and hopefully avoid a potiential problem. Besides, you can get the tape in some awesome colors now.

Isolating the dissimilar metals is also a good idea but may be more problematic, depending on the stress levels on the nuts/bolts. Bottle-cage mount screws probably can be isolated with bits of the same tape. Screws/bolts with higher stress levels may need stouter material (such as mylar or HDPE washers). Of course, if you're really into the galvanic stuff, you could hang some big bars of zinc off the seat. :lol:

 

[MrSteve]

'Trapdoor';
Peder, thanks.

Good suggestions!

I felt that this information must be shared, especially among those of us who actually
use our sweat glands to their maximum potential.


The FRP seat pan I laid up a few days ago has cured enough to trim.
It's strong, light and I can hardly wait to test-ride it.
No more seat corrosion problems for me!
That is, none related to galvanic corrosion....

-Steve

 

[wordy]

Re: Seat Pan - Cushion Scotchguard it

Depending on the cover material, Scotchguard will help repel dirt.

I like the idea of the FRP seat pan - a straightfoward solution than can only be improved by using that black carbon stuff!

Duglet on the Mazda Forum says this about Scotchguard:
..snip...
Yep it works brilliant...only problem...you need to reapply it after about 3 months..depends on wear. As it creates a small film/skin over the fabric which in time the seal is broken and needs to be recoated so stains and spillage bead off rather than soak in..