Author Topic: One way to restore a damaged finger wheel with clear resin  (Read 272 times)

Offline TelePlay

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One way to restore a damaged finger wheel with clear resin
« on: March 19, 2018, 06:19:27 AM »
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Most members have ended up with one or more open center finger wheels that have a part broken out of the center ring.

While it is always easier to toss it and find or buy a new one, the fun part of this hobby is to apply a little time, ingenuity, planning, resin and basic hand tools, they can be restored to near new condition. After all, it is a hobby and it's supposed to be fun and there is nothing more basic to this hobby and at the same time a lot of fun than to create a method from scratch out of research and thought that in the end turns out well, it worked. Others may want to post how they do the same thing with even better results.

The first image shows the damage circled in red and the latex rubber I used to create a mold of an undamaged area and the latex mold removed from the finger wheel.

The next shows the mold placed over the damaged area, the front, the back and the front held in place with tape.

The third image shows the back side with two pieces of wire being used to hold the mold away from the wheel so clear epoxy type resin could be poured into the damaged area. The center image shows the resin in place and the right image the wire removed and the mold held in place against the wheel with tape.

The last image shows the latex mold removed and preserved for another fix. With a bit of filing, and sanding the finger wheel was in the correct shape.

After shaping (removing excess resin) and a final sanding with 1000 grit dry sandpaper, a mixture of 5% MEK, 5% Acetone and 90% Denatured Alcohol was used with a high bite synthetic cloth to remove most of the sand marks and age related usage marks on other areas. The wheel was then fine sanded by using the same chemical mixture with a soft cotton cloth. Immediately after the final chemical sanding, Novus 2 was applied and buffed off with a Ryobi orbital buffer. Only one application on Novus was necessary after the chemical sanding.

The right side of the last image shows the once damaged finger wheel in what I would consider to be 97% new. It will certainly look just fine on a phone in the same condition.

The latex material took a few days to cure. Once the mold was cured and removed, this complete restoration was completed in less than a half day with most of that time spent waiting for the resin to cure. Shaping, sanding and polishing were completed in less than an hour.

Yes, it is easier to just toss the busted one in the junk and dig one out of a parts box, for those who have the luxury of having parts boxes, or just buy another from some source. This is being posted as an example of how one can use latex rubber and clear or colored resin to repair damaged items. It is being posted to help anyone interested in basic restoration techniques, such as this, get a few steps ahead on the learning curve. Quite easy to do and other than the Ryobi buffer, no other power tools were used in this restoration.
            John . . .

              

Offline HarrySmith

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Re: One way to restore a damaged finger wheel with clear resin
« Reply #1 on: March 19, 2018, 06:53:25 AM »
WOW! Great work John. That fingerwheel does look like new! Thanks for sharing the process with us.
Harry Smith
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there is only
do or do not"

Offline Pourme

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Re: One way to restore a damaged finger wheel with clear resin
« Reply #2 on: March 19, 2018, 08:18:48 AM »
Great work, John!....Thanks for sharing....

Benny
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Offline kleenax

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Re: One way to restore a damaged finger wheel with clear resin
« Reply #3 on: March 19, 2018, 09:22:31 AM »
Excellent work John!  You are much more multi-faceted than we know ;-)

When I looked at your photos, I swear I saw what looked like a wet Dorito laying on that fingerwheel! Turned out, it was actually your latex mold-making material.  Hope you don't mind the information below.....

I noted that you mentioned your latex mold-making material takes forever to harden up, so I thought I would share a pretty cool little product that works well, and cures pretty fast.

Called mold-putty (platinum-cure), it works very well with clear resins. You might want to check it out here:
  https://www.alumilite.com/store/p/1024-Mold-Putty.aspx 

Cool website; check it out!  Additionally, you will notice that they have many different clear resins to choose from. I worked for years with them to get a resin that doesn't yellow so much after casting; that is always a problem with casting clear parts. Clear resin that yellows over time will even effect pigmented castings because as we all know, if you add "yellow" to say a Blue phone, you get GREEN! Argh!

Alumilite is here in Michigan, I know them very well, and HIGHLY recommend! They're about 80 miles away from me, so Constance and I drive down to Kalamazoo to visit them often under the excuse of picking up supplies, but the REAL reason is that Bell's Brewery (Bell's Oberon and 2-Hearted Ale is the best!) is literally within sight of Alumilite's facility ;-)
Ray Kotke
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Offline TelePlay

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Re: One way to restore a damaged finger wheel with clear resin
« Reply #4 on: March 20, 2018, 02:09:17 PM »
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Ray, thanks for the link, and the complement.

Yes, Alumilite is the end all, be all (or at least one of them) supplier of molding and casting supplies. I got some pre-colored black from them years ago to fix something.

Everything I used to fix this wheel I already had in the basement. The latex was from about 10 years ago (and still usable), clear resin was from a few months ago for a non-phone project and the basic hand sanding and filing tools. I carved out time from another activity and used that to give this a try, my first attempt at molding and casting. If I'd known it would have turned out so well, I would have taken more time to prep the broken wheel, simple things like cleaning off the wheel and especially the edges of the broken out piece.

One concern was the inner 3 groves that hold the number card backer plate. Those would have been very difficult to reproduce in a mold and cast so this method is basically for fixing simple damage to the outer ring.

I have one more similar broken wheels so will take care to do proper prep and be more careful with the casting to see if I can get it to come out better. At least, this next time I will know better what I am doing and it may turn out better.

While not a perfect cast/restoration, hopefully this will give other members who are inclined to do this type of work a try.
            John . . .