Recommend a source or product for filling bolt holes in reclaimed boards

Drill out the holes to make them even, get some brass or copper rod, cut it a little longer, about 1/8”, than the thickness of the wood, and peen them to look like rivets.
Industrial Metals should have brass and copper in the diameter you need. A carbide saw can cut brass and copper without issue. Make sure you don’t burn your fingers holding the stuff as you’re making your cuts. B & C transferrs heat quite quickly…........ .... Jerry (in Tucson)

-- jerry (in Tucson)

Maybe a word will do?

Dutchman

Shape is up to you, either a matching wood, or a contrasting wood, 1/4” deep. Can even be different on each side.

-- A Planer? I'M the planer, this is what I use

I would just drill out a clean hole and plug with dowels. either a contrasting or matching color.

-- J.C.Sellers

Jerry, I will check out Industrial Metals. That could be an option.

Thanks for the other suggestions. I am mostly interested in a metallic option for a different look.

I didn’t mention it in the original post but I have ~ 75 holes to fill, times 2 because both sides will be done.

Lumber2Sawdust,

I don’t know if this would follow your design idea, but they are quite easy to make in whatever size you may need to cover those bolt holes.

Arts & Crafts pyramid wood plugs stained to contrast to wood finish of your choice.

...just a thought.

Best Regards. Grandpa Len
Work Safely and have Fun.

-- Mother Nature should be proud of what you've done with her tree. - Len ...just north of a stone's throw from the oHIo, river that is, in So. Indiana.

I’m not sure if plug cutters come in 5/8” size. If they do, I would drill a 5/8” hole everywhere there is a bolt hole; then cut 5/8” plugs from leftover wood of a contrasting wood and plug the holes. Either plane them flush or leave them proud. If not, use dowels of the wood of choice. Are the holes in a pattern, or are they irregularily located? If the latter, flush the plugs.

Brass plate some Carriage Bolts of the right size. Add a domed shape nut on the inside.

-- A Planer? I'M the planer, this is what I use

The nicest way of doing this I have seen to date, was to use car body filler with used printer catridge black toner and fill the holes or use epoxy clear resin with the toner.Obviously mix very thouroughly first and do it wearing old clothing outside preferably LOL no white dinner suits. Then simply pour or paste it into the holes and sand back later it looked stunning try on some scrap first to make sure you like it as much as I did.Alistair

-- excuse my typing as I have a form of parkinsons disease