Jonah said:
Hi all,
Recently pulled my boat out of the water, after purchasing it back in September. As in the image below, the bottom paint is showing through in many little specks. Time for a fresh paint job, or would this be alright for another season? The coat you see in the image was put on sometime in 2014, though I don't know the month.
Incidentally, I don't even fully understand what bottom-paint does, so I'd welcome an education along those lines.
Thanks
p.s. You can ignore the large, circular patches in the upper-right corner. The hull was wet there, and the camera flash made it appear a different shade of blue.
Bottom paint helps reduce the buildup of slime and growth as well as make the hull less attractive for things like barnacles to attach to. If you keep your boat in the water and the water is brackish or salty, you will attract growth and barnacles.
There are two )OK really 3) kinds of bottom paint: Ablative and hard coat. Each has different pros and cons and which is best depends on how your boat is used, how fast you cruise, whether it gets trailered regularly. etc. There are many articles online about bottom paint. Boat US has a good one so serf the web.
From the pictures, I would say that you could use a paint job. Touchup might be possible but that depends on what type of paint is on the hull and how old it is. It is far better to err on the safe side and paint considering what can happen if you don't and the existing paint doesn't work.
The main question to answer is what kind of paint is on the hull. If you wipe the hull with a damp rag and a lot of paint comes off, you have ablative paint. That paint wears away in the water constantly exposing new paint surface. Hard coat doesn't wear away and builds up over time until it gets thick, ugly and cracks. Hard coat has to be sanded. Ablative can be scrubbed or lightly sanded before new paint is applied. You can not apply hard coat over ablative. The ablative has to be sanded or chemically removed. You can in general apply ablative over ablative or hard but some extra prep will be needed for hard. It really helps if you know what brand of paint was used previously. Not all paints, even of the same type, are compatible
I have been using water based ablative paint for several years. It has its advantages, the main ones being that it doesn't smell as awful as non water based and it washes off you and your tools with water.
Ask around to see what other boaters are using and if they are happy with the results.
With any paint, use the proper protective gear and follow the manufactures instructions
I also believe that when it comes to bottom paint, you get what you pay for. Paint can run $60 a gallon to almost $300.
