Removing Bottom Paint

[Mako23]

Before I go through removing bottom paint off the mako ,I wanted to see if anybody has a ideas.



Mike

[dugout]

What kind is it and how many coats are there?

[Gary H]

Most marinas use a pressure cleaner that they inject sand with the water. Other than spending days with a D/A and 80 grit, that's all I know.

[Mako23]

The paint has been on the boat since I've owned it. Its a 79' hull who knows how long it's been there. The pressure cleaner alone will take some of it off, but i don't want to get to close. The last thing i want to do is D/A and 80 grit

[WreckDiver]

This is what you want right here & it works.

Seahawk Paint stripper ----> Seahawk (http://www.seahawkpaints.com/strippers.htm)

[Pucho]

Dont know the cost but you can ask in your are for the service.
http://www.sodablastsystems.com/

Pucho

[Spear One]

The benefit of removing the paint with a light sandblast system is, not only does it remove the paint much more effeciently, it also leaves you a well prepared surface for the new primer and paint. I know that many folks will tell you that you do not need a primer, but I think that a coat of 2 component epoxy primer on a properly sandblased finish makes a perfect surface for you bottom paint to adhere to. I did this to my commercial fishing boat and we never had a peeling problem with bottom paint in the 13 years we owned it.

Make sure you sand thoroughly between coats, especially the primer coat. In addition, if you spray instead of brush and roll, you will get a much smoother/slicker surface to your bottom and thus greatly reduce drag. This can be very important on a planing hull, especially if you carry heavy loads.

[stevemc1]

I have worked in marinas before I started with the fire dept, and though I didnt do any bottom paint removal, they used a pressure cleaner, and got right up to it, and then used a sand blaster with water. If you dont want any paint on it and want a smooth surface, I would try the stripper, and pressure clean it off once it has softened the paint. Sometimes they would not pressure clean it with sand, as in new first time painting, and they would paint a primer called skip sand, but that was before epoxy barrier coats came out. Now a days, epoxy barrier coats with ablative bottom paint on boats that stay in all the time, is the only way. If you are going to keep it on a trailer, you will notice it goes quite a bit faster with no bottom paint.

[zenspearo]

That bottom paint stuff is deadly toxic. Be very careful. There's a reason why marine animals die when they try to attach to the bottom.

If it's a Mako 23, and you have a trailer, plan a trip to Baja.

Drop it off at the yard, go spearing for a few days, come back--done. They will have the right gear to handle that stuff (at least the yard I go to) and for a fraction of the cost that it would to do it here (or the cost if I were to do it myself), they will get it done, and you will have a nice vacation to boot.

How do you think I schedule my boat maintenance? Seriously.

[dugout]

There are really three choices;
Chemical stripper
Grind it off
Sand Blast it off

There is a water jet planner, also, but you are talking big bucks and it's usually only done on hulls with bad blister problems.

Chemical is the only choice which will leave the original gel-coat intact.
Grinding and sand blasting will require a two-part barrier coat before the new paint. You need something on the hull even if it lives on a trailer or a lift. It's a mistake to sail a bare gel-coat hull. Gel-coat is extremely porous.

It's all ugly; it's all expen$ive; it's all a lot of work. Pick your poison...
Follow with a good barrier coat and ablative paint.

I had 12 coats of dead anti-fouling paint taken off a 84 Albemarle 27'. All said and done, it was 5 grand to have it done and worth every penny, to me.

[PAT A]

Most marinas use a pressure cleaner that they inject sand with the water. Other than spending days with a D/A and 80 grit, that's all I know.


Whatever you do, do not dry sand or grind that bottom paint, it is highly toxic as stated in an earlier post. If you dont know exactly what you are doing with that stuff, spend the money and have it professionaly done....PAT

[Slay Ride]

Can I ask why you would want to take it all off? Sand it down nice and put on another layer. Areas that thick, sand a little more. Just because it's been on since 79', I don't think that's necessarily a bad thing. I'm sure that over time most of it's made it's way off the boat and been repainted. Maybe I'm missing the boat, but having a good solid base that is obviously bonded well is not a bad thing.

[dugout]

Slay Ride;
A lot has to do with the type of paint and how much of it is on the hull. Paint holds mosture, (read as weight), and this trapped mositure can lead to blister issues. The paint, itself, is heavy. Fuel economy and potential for blisters are the reasons many, like myself, go through the ordeal of removal. It's a one time deal if Ablative paint is used after it's done.

[Surface Tension]

Will you be leaving it in the water? If so, I would go with Slay Rides suggestion.

Otherwise, if you are careful, you can remove it and restore the original gel coat.

Older boats tended to have very thick coats of gelcoat on the bottom. I took the bottom paint of my 86 Rampage and you can see your reflection in the bottom now. Here is a picture of it before and with it partially clean. It was a lot of work and I had to jack the boat up and move it around to do it on the trailer. I felt this was safer than putting it on blocks; for me and the boat.

http://www.imagestation.com/picture/sraid221/pcd63e638ddda991a32e1cd6150559bca/eb725e2f.jpg

http://www.imagestation.com/picture/sraid221/pe4424873e9912e1db11f1e868dd21180/eb724ea8.jpg

I used a fiberglass safe paint stripper, and it took two passes. Although it was fiberglass safe, don’t take it all the way down to the gel coat because you will damage it.

Then comes the fun part. Get a good mask, like a 3M N100 8233. Don’t waste your time with the dust masks from Home Depot. Bottom paint has copper in it, not lethal but you don’t want to be breathing it. I think some older paints used mercury, but they have been illegal for some time. This mask would still do the job.

Use only a palm sander. A belt or rotary sander will put gouges in the bottom.

I used 80 grit to take off the remaining bottom paint. Then 200, then 320, then 600, then 1200. Wet sanding the last two would be the best if you have access to a large supply of compressed air.

As good as the 2 part poly bottom enamels they sell today are, I still think gel coat is more durable. Not to mention it would be cheaper than having to buy new poly 100+ a gallon.

Have fun. My eyes burn and hands ache just thinking about it! If you've got money, it's a great project to hire someone else to do!!

Dave

[Slay Ride]

Slay Ride;
A lot has to do with the type of paint and how much of it is on the hull. Paint holds mosture, (read as weight), and this trapped mositure can lead to blister issues. The paint, itself, is heavy. Fuel economy and potential for blisters are the reasons many, like myself, go through the ordeal of removal. It's a one time deal if Ablative paint is used after it's done.


OK, cool. I completely understand and agree with this. I've only used Ablative paint in the past. The issues that you mentioned can be "seen" to a certain extent. I guess my point in general was that it may not be necessarily imperitive to strip absolutely all the entire boat unless issues are actually occuring (mainly blistering- excess wieght can be sanded off). Just taking paint off a boat to take the paint off because it's old may not be the best choice in general. But in my vacation I did not stay at a Holiday Inn so maybe I should just shut my pie hole. I did a complete bottom job on my boat last year. That is a tough job no matter what. Fitting that have not been removed in 10 years. Intakes, tabs........it's a ton of work, not even thinking about taking all the paint off. Good luck.

[eyyeball]

I did a complete bottom job

!

[dugout]

My hat is off to you! I wouldn't even consider doing a bottom refit. There are some things I just let the yard do.
Your opinion is spot on regarding ablative re-coating, too. I would never consider taking off ablative paint. That is the great thing about it. If it's there it's still good and working. A little pressure washing, paint it and you're good to go... :thumps:

[BLACKFIN]

Soda blast it off. If you want it done correctly.

[hairdo]

If the bottom paint still looks good and the barnacles are minimum can you just clean the surface (remove build up) and put the boat back in the water or should it be repainted?

[Mako23]

The boat is on a trailer and will probably stay on a trailer. I would like to get the bottom repainted with a smooth hard paint. The bottom paint now is black , I was told the bottom paint will stain the gel-coat and i will have to repaint with a dark color.

[Surface Tension]

The gel coat that was underlying the bottom paint of my boat is the same color as that above the water line (see picture). My boat sat in the water for over twenty years and had several coats of bottom paint on it.