You pose an interesting question… and similar to one that I’ve been considering: what is it with those who don’t seem to want to know much about hydrodynamics or construction but are all over how to get their ( fill in your favorite term here) graphics on the thing - that’s their priority. Kinda putting the cart before the horse, in my far from humble opinion.
But, leaving that one aside…
Why make a board look good on a repair? My first and most important answer is, I’m getting paid for it!! And if it looks like hell, I may have a little trouble getting the money. If I’m doing it on my own board, I could maybe get away with a less cosmetically good job and just go for function, if I wa spressed for time…but if somebody is considering that repair on my board and considering having me do theirs, if mine looks like hell then they are gonna find somebody else to give the money to. Not good.
Another thing - some of how well a board performs is psychological. On a given day, effectively identical waves, give somebody a board with, say, a color job they hate and then a fuctionally identical board that is colored…or not…the way they like, and they will say they those two boards perform better. 'Cos the readout isn’t digital, it isn’t analog, it isn’t even binary…it’s all in the mind.
Is there a difference between a board repaired with the repair flush with and contoured to the original and something that I am gonna refer to as a hack job?? I think so, though I can’t prove it empirically. You have a thing that’s operating with a fixed amount of power: the wave, and anything that might cause extra drag is gonna make that thing less fast. Turns, probably different both due to different flow patterns and due to the extra parasitic drag of the hack job. Granted, that’s not a lot of difference, but it’s there. Then there’s strength - if there’s a real disruption in the glass, a place where the structure changes abruptly, you have a trigger point for where a stress can and will break it.
As an aside, if somebody tells me that an imperfectly shaped board with lumpy rails and bottom to it doesn’t matter, I’m going to either be waiting for the punchline or immediately write this joker off. He’s talking out of the wrong end of his gastric system. He may think he knows something, but so do the Flat Earth Society members, in spite of proof to the contrary. And if said ‘authority’ is attempting to peddle boards to me that are lumpy, unintentionally assymmetrical and such and telling me that that doesn’t matter, I’m gonna tell him that he hasn’t got a clue in very unkind terms and heave his ignorant…carcass…out of my shop permanently. That’s not a valid theory, that’s an excuse for a lack of basic skills and nothing more. .
Now… why do a good job of repairs? Ok, unless it’s going to be literally five times the work, my answer to that is why not do a good job? A good job is not going to leak, 'cos that’s part of the job and part of the system of doing it right. It’ll look good, 'cos the original glass has been saved as much as reasonably possible and the necessary filler is behind it - beware of anybody who suggests that the right way to fix a board is by cutting, chopping and sawing away any damage, it only makes more work and a bad job in the end. It’ll be strong, 'cos that original glass is tied in with the new work and it’s got structural continuity restored as much as possible.
I mean, yeah, you can just slap a patch of cloth over something, slap on the resin messy and call it good enough, but what are you saving? Five minutes working time and maybe 45 minutes to an hour of waiting for the additional resin to set up? And that’s without power sanding. If that’s the only concern, put on an appropriate temporary patch and do it right when you have the time. It’s easy enough, otherwise I wouldn’t be doing it.
doc…