I just had some done this fall. The simple answer is it is easy. The longer answer is the work is not so hard but it's not totally easy. Wet sand, fill, prime, paint
, buff. We wet sanded with 1000 wet paper then filled. The primer was done and the next day it could be painted. We were hauled out at the time and being hauled does save a lot of time and hassle. We did the stripe on both aft quarters and both sides of the bow so that was about 4 sections 3 ft long each.
The color matching is more by guess with a bit of art thrown in. You'll never match it dead on given 10 years of sun and the new paint
will have a different shine that also effects the color in ways that are hard to describe. Mine were some deep scratches into the gelcoat
in the aft quarters plus removing an old boat name applied in white and gray Alwgrip over green Alwgrip stripe.
For minor light scratches that don't go through the paint You may be able to buff most of them out. That was how we restored the area we removed the name from and it worked exceptionally well. A 2000 grit water
based compound applied with a machine will get you pretty close. Air powered buffer is the lightest to hang on to. An electric
buffer will destroy your back. We eventually did the whole hull
with it and the gelcoat
brightened up a lot too.
The shine had dulled on the entire dark green stripe. We buffed the entire stripe after we filled and painted the aft quarters. A lot will depend on how thick the paint really is. You can lay down Alwgrip pretty thin yet be very opaque or it might be quite thick. Mine was quite thick as we wet sanded the old name off both sides of the bow without actually going all the way through. Some buffing may reveal the original color / shine better than just painting over it. This can help match the new shine of the new to the old paint.
The color matching problem is not so easy. You prep it all up sanded, filled and primed masking off a larger area around the spot, then it takes a while to let it dry and buff it to really know how it looks. If it is too light or too dark you have to wet sand it off and do it over. That can add another two days. If it is perfect the paint you mixed is no longer usable. So the rest of the job has to be remixed. So you have to decide if you want to go for it on the first try. It's not easy to get the recipe perfect and if you did it one time for a test mixing, making enough a second time the same way isn't easy. You'll most probably have to settle for "pretty close" if you get it. Using the same Alwgrip color as the original won't be close enough so you have to use a little adjustment.
Mine started with a forest green that was too bright. We added a few drops of black and it went from being far too light to a just a little bit too dark. We went with the slightly darker attempt. After all the buffing it was close enough and far better than it was with the deep gouges. The buffing in the areas around it made the shine match better. I know where the areas are but they are not easy for me to see. If I told you where to look you might be able see them from the dock
. No one can see it on the water
. You could have seen the scratches a long way away on the water.
Good luck with your job. A good sprayer is a valuable tool. Someone that mixes Alwgrip isn't a bad person to know either. You won't use much paint at all.