I have a 290 wellcraft coastal, it has existing bottom paint, stays in water most of the time. What product do you suggest for repaint and should i prime before. I have pressure wash the boat all lose paint is off,
Are you in salt water? If so
Cukote bottom paint is a good choice; if in warmer water or are in a heavy fouling area, you may wish to upgrade to
Biocop TF the best for harsher conditions.
For fresh water
AF 33 with some
Bioboost to guard against slime would be sufficient. See our
Ablative Bottom Paints/
Bioboost.
Usually if the existing bottom paint is in good condition you can just scuff with 80/100 grit, rinse, dry and apply as most bottom paints are compatible. If the current paint is flaking off or really think and you’re removing a large portion or it’s going to the fiberglass you should prime with something like
Barrier Coat Primer.
(06-22-2012 08:01 PM)BottomPaintStore Wrote: [ -> ]Are you in salt water? If so Cukote bottom paint is a good choice; if in warmer water or are in a heavy fouling area, you may wish to upgrade to Biocop TF the best for harsher conditions.
For fresh water AF 33 with some Bioboost to guard against slime would be sufficient. See our Ablative Bottom Paints/ Bioboost.
Usually if the existing bottom paint is in good condition you can just scuff with 80/100 grit, rinse, dry and apply as most bottom paints are compatible. If the current paint is flaking off or really think and you’re removing a large portion or it’s going to the fiberglass you should prime with something like Barrier Coat Primer.
Just pulled my boat ( USY 18-freshwater) & pressure washed it . I had some Interlux ACT bottom paint left over from last year ,and I wanted to use it before it solidified in the can. The paint was powdery and rubbed off on my hands .To avoid painting over loose paint ( I've done enough houses to know). I thought that a wipe with DENATURED ALCOHOL would do the trick, and the local boat repair guys thought so, too.( well. it seemed like a good idea at the time). Naturally, the alc acted as a solvent and all the bottom paint below the waterline came off ( Suprisingly, paint above the waterline was solid). So I scraped it, feathered the edges and put on the paint. Now, I see that
Interlux recommend 60 day max to put the boat back in. I don't want to put her back in in Feb, so I was thinking that applying another coat before launching in the spring might be best. What do you think???
So for future reference what would have been the RIGHT thing to do?
Thanks for your help
The best thing to do would have been to sand the existing coating with 80 grit sandpaper to remove the oxidation on the old coating. After the sanding, you would just need to rinse of the residue with water and let it dry before painting with a new coat. When you put on a new coat of paint, the adhesion of that coat to the previous coating depends on a couple of things.
1. You should make sure that you give it a good 80 grit sand and rinse properly as described above. No solvent wash!
2. Longterm adhesion depends on how many previous coats are on the hull. If there are several layers of old paint, the new coat will soak through and lessen the adhesion of the underlying coats. This is due to the solvent penetrating through to the underlying coats and may cause them to let go and peel off. So if you have several layers, it is wise to due a thorough sanding to remove some of those old layers. You saw this first hand with your solvent wash!
Interlux does say not more than 60 days, but you can extend this significantly by pressure washing the boat (lightly) before you launch the boat. The reason why the say 60 days is because the paint will oxidize and that chaulky outer layer will have limited antifouling characteristics. With a light pressure washing you will remove that oxidation and expose a fresh layer of paint with good antifouling characteristics.
Be sure to put on at least two coats of paint... The paint you are using is designed to wear away overtime. The pressure wash will remove paint, so you need to make sure you have enough paint on there to withstand the pressure wash and get you through the season!
(12-09-2012 11:44 AM)BottomPaintStore Wrote: [ -> ]The best thing to do would have been to sand the existing coating with 80 grit sandpaper to remove the oxidation on the old coating. After the sanding, you would just need to rinse of the residue with water and let it dry before painting with a new coat. When you put on a new coat of paint, the adhesion of that coat to the previous coating depends on a couple of things.
1. You should make sure that you give it a good 80 grit sand and rinse properly as described above. No solvent wash!
2. Longterm adhesion depends on how many previous coats are on the hull. If there are several layers of old paint, the new coat will soak through and lessen the adhesion of the underlying coats. This is due to the solvent penetrating through to the underlying coats and may cause them to let go and peel off. So if you have several layers, it is wise to due a thorough sanding to remove some of those old layers. You saw this first hand with your solvent wash!
Interlux does say not more than 60 days, but you can extend this significantly by pressure washing the boat (lightly) before you launch the boat. The reason why the say 60 days is because the paint will oxidize and that chaulky outer layer will have limited antifouling characteristics. With a light pressure washing you will remove that oxidation and expose a fresh layer of paint with good antifouling characteristics.
Be sure to put on at least two coats of paint... The paint you are using is designed to wear away overtime. The pressure wash will remove paint, so you need to make sure you have enough paint on there to withstand the pressure wash and get you through the season!
Thanks a lot mate. That answers my question.