What filler for inside corner seams?

[John Huber]

I have made a prototype of a "soccer ball" dome. It is 10" in diameter and the seams are 2" long. Despite my best efforts (I've learned a lot; that's why its a prototype!), there are errors at the seams. The interior seams have me baffled. What filler should I use? How do I smooth the filler once it is cured? It seems to me the most difficult part will be the center interior seams, because of limited access and angles of approach.

As you can see from the photo, there are many seams and many of them are across the grain. If I sand along the seam, I'll have cross-grain scratches on many edges. Would a water-wetted carving gouge with a round profile get the filler smooth enough before it cures?

Thanks in advance for any advice you can give me.

[Cliff Rohrabacher]

Congratulations !! All those compound angles are rather tricky aren't they. I have completed most of my finger jointed sphere made up and it's a fair bit like yours except that the pieces are finger jointed at compound angles and the pieces are made of of strip stck 1" inch high by 1/4" thick.

Have you considered connecting the pieces with smal 1/8" thick splines that will show on both the inside and outside?

As to the seams. A lot of guys who build sculpted chairs like Maloof Rockers use expoxy mixed with saw dust to fill in those little voids where their joints are not so perfect.