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Here is a recent project.

Old Gon Bops
IQ3000
CL3000

Shells heavily battered with deep gouges.
Quinto cracked glue line top to bottom in 2 locations, held together only by external hoops.
Each shell missing 2 external hoops.
Skin on conga rotting due to rusting flesh ring,
Hardware showing areas of rusting through chrome plating, but all hardware intact.
Crown on quinto warped.
Lugs in remarkably good shape, I think due to the fact that they were heavily caked with old grease.

Before

Project is complete, so this is more of a photo essay, maybe to inspire the do-it-yourselfers
Here we go….

One of numerous gluing sessions.
A picture of quinto clamp-up: 1 ratchet strap, and 3 Spanish Windlass rope clamps.
That shell is stapped tight…to the point that I thought it might implode.
Yet I was unable to close joint on the exterior surface, which made for a wide glue line on exterior.
Interior of joint was closed tight

I peel off the old Gon Bops identifier stickers, and press between sheets of wax paper to save for reference. I won’t put them back on.
I also removed the hardware for hanging shells on a (Gon Bops?)stand, as I don’t intend to use them, and not having them simplifies and cleans up the look of the finished shell.

Crown for Quinto is slightly warped.
Inspection of inside of crown shows warp occurred at weld where ring of metal was fused together, which indicates to me warping happened at manufacturing process. It has most probably always been warped.
Not a lot I can do about it.


Sideplates looked pretty rough.
I used a 3 stage process to clean them up:
1. Steel wool to “sand” down rust.
2. Phosphoric acid to convert surface rust (from iron oxide to iron phosphide)
3. Polishing metal with rouge stick and buffing wheel

Preparing for hoop fabrication, establishing height / placement location of exterior hoops

I really must express my sincere thanks to Zeno and his topic for inspiring me attempt this.
http://www.mycongaplace.com/forum/eng/viewtopic.php?f=5&t=1746&hilit=making+hoops

Zeno’s thread really tells you all you need to know to fab hoops.
Consider the following postings an elaboration his topic.

Thanks Zeno, maybe you could repost some of the photos on your excellent thread…a lot of the links are dead.

Following photos may help to give a visual guide as how to make your own.

How is this helpful?
1. You will see a home-made process of fabricating hoops to replace broken or missing.
2. You will see the process of making templates to have your hoops made locally at any sheet metal fabricator, or to send templates off to drum makers for fabrication.
3. By making templates you could save the cost of shipping drums back and forth, and could install hoops on shell by yourself

Fabricating hoops or templates at home is a “one off” process as opposed to the production process of the drum makers.

This is my bumbling learn-as-you-go process.
A crude but unhesitating execution of my ideas

The idea is to make accurate templates.
It is a much easier to work with stiff paper than it is to work with metal. Get them right.

Making templates is a matter of transference. There is not much measuring involved.

At the risk of getting too mathematical:
A conga shell is a complex geometric shape: a barrel which is composed of compound curves: it curves towards the ends as it curves into a round shape.

To begin we must super-impose a simple geometric shape – a cone (think ice cream cone) over the complex compound curve barrel to find the plane of intersection of these two shapes, which will establish one edge of the hoop.

Pictures are worth a thousand words....see next post.

The easiest hoop to trace is the one at the foot of the shell.
Pic 1
Simply make a cone of stiff material (I used roofing felt or tar paper, because I had a roll of it).
Remember as the conga shell is curving in towards it ends, the paper of the cone will only contact the surface of shell completely, in a small area of intersection.
The idea is to get that area of cone contact where the hoop will be located on the shell.

Once cone is properly placed, simply cut off pointy end of cone, reach in and trace bottom edge of shell onto inside surface of paper.

Pic 2
I cut a piece of wood to the width I wanted hoop to be (1 1/8”), and used it as a gauge for all other transfers.
Remove cone from drum, lay out flat, use gauge on first line tracing to scribe second line which will define width of template.

Pic 3
When tracing line onto cone, due to overlap of paper, the template will be the exact circumference of the shell.
In order to fasten ends of hoop together, there must be overlap.
I folded over traced shape to make a projection of continued shape for overlap and labeled if “rough end”

Pic 4
Overlap on template

A different transference technique is used for hoops on middle of shell.
Masking tape placed below location of hoop, where an offset line of reference is plotted.
A marking gauge is then used to plot bottom edge of hoop onto another felt paper cone.
Once bottom edge is plotted, as explained in previous post, 1 1/8” wooden gauge is used to establish width of hoop on laid out felt paper.

Transfer templates are cut and laid out on a fresh piece of felt paper.
A thin wooden batten is used to smooth out the roughly traced curves.
Finished templates are cut from “smoothed” lines

Aluminum stock for all hoops cost $16.41. Sold by weight.

The aluminum used on original Gon Bops hoops, is quite thin. I scaled up the new hoops to the thickness of the hoops used on Isla Percussion drums.

Folded a piece of aluminum until it approximated thickness of Isla hoop and brought that to sheet metal shop as thickness sample.
I could have made my project easier by sticking with original thickness of metal, which was thin enough to be cut with heavy scissors, instead of snips.

Now that they are complete, I’m glad I used thicker material, it has a more substantial look and feel.

After jigsaw cuts, each shape trimmed to tracing line with tin-snips.

Tap-tap-tap flat shapes into circular shapes. Quick and easy.

After rough fabbing hoops, and completion of numerous glue clampings, refinishing began.

This may be sacrilegious to some, but I use power tools.
Belt sander and orbital sander to remove old finish, switching to hand sanding at bare wood.

Secret to using power sanders: never stop movement of sander, always sand with grain

After preliminary hand sanding, prior to wood filler treatment.

Notice photo-imprinted image of exterior hoops onto wood surface.
Also notice differing colors of wood staves.

A wipedown with mineral spirits after sanding gives a good idea how un-stained wood appears under a finish coat.

Great work Joseph . I learned a lot form your pic s . Those Gon bops look great . I like the way you made the template for the rings .thanks for sharing your project and all the tips you used I'm sure they will benefit many who visit this board .

M