Fumbletrumpet

Pipe clamps are an excellent system that I have see in the USA, but we don't really have them here in the UK (our pipe is metric and all too often plastic or copper - threaded imperial steel/iron pipe is hard to source).

We do however have a sort-of 'system' of clampy type things which fit into the standard holes within a 'Workmate' (do you guys have these sort of folding benches ?) or its cheaper clones. These hold-downs (we sometimes call them 'dogs') may not be available in the USA, but if they are, why go to all the trouble of making something that already exists as an off the shelf product ?

Anyways, how often do you need a clamp in the middle of a board or bench ? Easiest of all must be clamp near an edge with a ratchet clamp or lever a hold down timber batten off a slightly thicker than workpiece shim with the clamp in between (sorry, needs a pic to explain really).

Like the pipe clamp system, just seems a lot of work to me.

Yes, I'm with the other posters here, its a weak repair unless there is some bond around the hole and patch edges.

For myself I glue some smaller strips on the back of the board (with Gripfill/No Nails) and clamp if necessary (the strips sometimes fall off inside the framing void if too large/heavy for the glue), then glue the patch in place so its supported by the strips of board.

The patch needs a gap of 1/8" all round and chamfer off the paper around joint edges with a knife.

Here in the UK we often use PVA diluted 1:3 as a 'size' when skimming drywall or any absorbent surface and I'd brush some of this around the chamfered edge gap to ensure the board joint compound really sticks the patch in place.

I also agree that the paper flap creates too much of a 'witness' in the final finish which requires too large area of skim to feather out. Nice to see a different way of doing this though, thanks.