mtv wrote:

8GCBC wrote:If your first time...

Check with your mechanic about the materials/condition of the keel/hull before touching anything not water. Some floats do not have a steel keel to save weight.

I've never seen any floats with steel keels--what kind of floats are you referring to?

I've landed a set of amphibious floats (aluminum, including keels) on the keels on asphalt twice due to gear failure in transit. No damage, though did scrape up the keels a bit, which was to be expected at that point. A chat with the manufacturer said to measure the remaining keel depth, and if it met a spec, and no other damage, pedal on.

This was Kodiak, and no grass runways anywhere near, or I'd have gone there. But, no big deal in any case.

MTV

Steel keel is an option on 2100As at least I thought it was. (10) LBS. Need to look at 337 STC again.

Might be wrong the main keel looks like it's aluminum 6061-T6. I thought I ordered steel. Glad I looked. Thank you. Called Wip it's discontinued.

https://www.wipaire.com/wp-content/uploads/2016/11/PM_2100_Scout.pdf

Wip has a steel wear strip (and full keel) option on some models and I was just told they experimented with steel but went back to aluminum on 2100s. I appreciate the admonishment!

Keel steel wear strip part Wip # 6S01200-002 (S) or can be fabricated in shop:

Main full steel keel also Wip # 4S01354-008 (S) is still available:

Not an admonishment--just a question. always interesting to know what was tried.

MTV

mtv wrote:Not an admonishment--just a question. always interesting to know what was tried.

MTV

Me too. Learning everyday... 6061-T6 is what I have.

Yeah, it would be interesting to know what sort of corrosion issues a steel strip next to aluminum would generate, especially around salt water.

Interesting in any case.

MTV

mtv wrote:Yeah, it would be interesting to know what sort of corrosion issues a steel strip next to aluminum would generate, especially around salt water.

Interesting in any case.

MTV

Its not an issue if insulated with a dielectric material. Or it could be a nightmare of galvanic corrosion. There are many steel and aluminium structures together which are fine with proper engineering & maintenance in saltwater. But, if possible the best by far are materials with the same electronic potential.

A removable wear strip is the best in my opinion. The material could vary in weight, corrosion potential and toughness depending of what may suit the operators needs.

I'm sitting on an aluminum boat right now at the Ala Wai ( tropical water is notorious for corrosion) with steel hardware attached above and below the waterline. It generally is OK unless the insulation wears off etc. The sacrificial zinc anodes last about 3-6 months. I keep shore power and house batteries off in case of any stray current.

A UHMW wear strip would be the ticket I'd think.

Actually, damage to keels is really pretty rare, and nearly always associated with a catastrophic kind of event.

I've flown and owned floats that had literally thousands of hours, lots of use and abuse, and were fifty plus years old with original keels that looked great.

Wear strips would be hard to attach securely, and if one started coming off, you probably would never know it.

MTV

River rat wrote:A UHMW wear strip would be the ticket I'd think.

Interesting idea. There are many space age materials/engineering techniques that simply were not around when the majority of float STCs were developed. Just like my C3000A hydraulic wheel skis have sacrificial UHMW on the bottom. Not sure what Wipaire was designing the specific wear strip for but, there must of been a customer or operator that would benefit from it. The company sells floats all over the world for many operations. Wipaire is constantly maintaining/overhauling customer's float too. So, I'm sure the wear strip option(s) must satisfy a mission somewhere.

Need more questions answered? I love Wip's (24)x(7) telephone hotline, I can wake up in the middle of the night anywhere in the world if something is bothering me about my STC(s) and get technical guidance.

Well to pick a nit, the UHMW on ski bottoms isn't really there for wear necessarily...it's there for sliding, and to prevent freezedown. Try working a set of skis with metal bottoms and no UHMW sometime, and you'll see what I mean.

MTV

mtv wrote:Well to pick a nit, the UHMW on ski bottoms isn't really there for wear necessarily...it's there for sliding, and to prevent freezedown. Try working a set of skis with metal bottoms and no UHMW sometime, and you'll see what I mean.

MTV

Ahhh yes good point and...

UHMW is lighter than many metals, has an almost infinite yield point (doesn't dent easily, not malleable) and is also easily replaced when worn too. Unfortunately, aircraft skis run over all kinds of s<edit>. Especially in areas with a dry mild Winter.

UHMW is described as very abrasive resistant in Wikipedia:
https://en.m.wikipedia.org/wiki/Ultra-high-molecular-weight_polyethylene

...has extremely low moisture absorption and a very low coefficient of friction; is self-lubricating (see boundary lubrication); and is highly resistant to abrasion, in some forms being 15 times more resistant to abrasion than carbon steel. Its coefficient of friction is significantly lower than that of nylon and acetal, and is comparable to that of polytetrafluoroethylene (PTFE, Teflon), but UHMWPE has better abrasion resistance than PTFE...[5][6]

Thanks for all the replies; this went well.

A nice 10kt wind, and our first morning with frost, seemed to provide ideal conditions. My main concern was a nose over tendency, but I sensed none of that.

Skis go on next week!

Glad it worked out for you. That is an intimidating program the first few times you go there. It's actually pretty amazing how well it works.

Good job!

Take care,

Mike