Apr 12, 2010

UDT Modification Update...


I've been fiddling with my latest pair of Voit UDTs for about 4 months now, making changes in the length, flex, foot pocket padding, and heel strap padding in small increments.

I finally got the foot pocket padding right, so I committed the combination of two full length 3mm wetsuit pads, one 3/4 length wetsuit pad, and one plastic top stiffener to a more permanent state.

As you can see, I sandwiched a thin sheet of water-jug-plastic between layers of neoprene using a spot bonding technique. No easily obtainable adhesive (that I know of) will stick to that plastic material, so I allow the neoprene layers to bond to themselves through holes punched in the plastic and a narrow rim around the perimeter. This firmly holds the plastic between the neoprene layers. (The bonding glue was Barge contact cement.)

The plastic was pressed onto one side of the neoprene after the contact cement had dried to the point where it was ready to be fit onto the other layer of neoprene. (About 20 minutes.)

After the neoprene/plastic sandwich was complete, I tucked the "tongue" back into the foot packet, yielding this result...


I began using the plastic inserts on the inside/top of foot pockets when Voit Duckfeet started putting softer rubber in the foot pocket area of their fins back in the 80's. UDT's have very good foot pocket rubber, but over the years I've learned that I like a really stiff foot pocket (which is padded with neoprene) and a more flexible blade.

I've used as many as three layers of plastic on some poorly made fins, but one layer is sufficient on UDT's.

10 comments:

Anonymous said...

Does anyone try trimming down the heel strap? I feel like it doesn't need to be 2" tall to do the trick. I'm getting ready to jump in with both feet on some fin modifications.

PG said...

GG trims the width of his UDT heel straps down a bit using a dremel tool with a small sanding drum. Not sure how much, however.

Jamie said...

I've tried trimming the heel strap down, but ultimately didn't like it. Obviously I didn't do as good a job as GG does, so it wasn't really comfortable, but I've left the heel strap intact on my last pair and like it much better. Plus cutting down the heel straps make them weaker and more prone to breaking if you are tugging on them, and probably moreso as the fins age and the rubber begins to break down

Jamie said...

So Paul is the insert only glued to the outside//top of the fin, and not inside the footpocket at all?

PG said...

The insert is between two sheets of neoprene, which is tucked into the inside of the foot pocket.

Anonymous said...

is there a way to trim the ribs cleanly without powered tools?

PG said...

It's pretty difficult to thin out stif fins without a power sander.

You can use a sanding block with 80 grit wet/dry sandpaper, or a razor plane set at a VERY light cut.

Either way takes a lot of time. (Like days.)

Mateo said...

very clean mods paul...i especially like that inside-only heel strap pad.....

Celida said...

Paul, thanks so much for the pocket stiffener idea, just tried it in a pair of Churchills and it REALLY improved the thrust.Thanks also to Matt for the link. Cheers, Ken M

Muir said...

I only trim where I burn holes. For me that is putting a dip in around the outside of the ankles.