Hull cleaning

Z

zuunami

New member
Very new to us 2006 16' cruiser was left in the saltwater too long :) I've tried using CLR on the bottom of the hull, and it works, but tedious. Anyone have any preferences about what to use to take off those heavy bottom mineral deposits? It's also very oxidized, especially the green strip and bottom, going to start with Meguiar's Oxidation Remover, but anyone have other products they love? thanks in advance, soon I'll be able to more easily navigate the site to find the right past posts :)
And, I hope I've properly uploaded this photo of a portion of the hull :)
[http://www.c-brats.com/modules.php?set_albumName=zuunami&id=K01_1631&op=modload&name=gallery&file=index&include=view_photo.php][/img]
 
let me try that image insert one more time... :)
K01_1631.sized.jpg
 
That appears to me to be barnacle bottom plates. They produce a glue which is as tough as any man made adhesive.

Start with fairly mild acids: Oxalic Acid is one I use. You go to a paint store and get a life time supply for about $20. Lowes and Home Depot should have the powder. Make a saturated solution.

Phosphoric acid is next on the scale. Barnacle Buster These both take some time, you have to soak the calcium to get it off of the gel coat.

Use some of the mildly abrasive scotch mesh pads. Just put pressure on the barnacle plate, not the gel coat.

As a last resort: use muriatic acid. This is powerful stuff--it is a very acid material. I use a respirator, full body suit and head of tyvex, and heavy vinyl or nitric gloves. In other words you don't want to breath the fumes or get the material on the eyes or skin!

The nuclear option is: You can take them off with a scraper. You can sand them off. But that is damaging to the underlying gel coat.
 
thanks, Bob, yes I've seen Oxalic Acid in a lot of products. For the powder, what do you mean by a saturated solution? We use muriatic acid to shine up abalone shells, tho unfortunately not with as much protective gear as you - we wouldn't want to try this on the dory, it sits on concrete pavers in the driveway and I'm afraid they would melt :) I assume the "barnacle bottom plates" aren't going to continue to grow if we don't get them off in the next day?

and I guess it wouldn't be a good idea to do bottom paint until we get that cleared off :)

thanks again
 
zuunami":qcjfnlk2 said:
thanks, Bob, yes I've seen Oxalic Acid in a lot of products. For the powder, what do you mean by a saturated solution? We use muriatic acid to shine up abalone shells, tho unfortunately not with as much protective gear as you - we wouldn't want to try this on the dory, it sits on concrete pavers in the driveway and I'm afraid they would melt :) I assume the "barnacle bottom plates" aren't going to continue to grow if we don't get them off in the next day?

and I guess it wouldn't be a good idea to do bottom paint until we get that cleared off :)

thanks again
Click to expand...

Saturated solution is to add crystals until no more dissolve.

Hmm, never tried muriatic acid on abs...but they used to be plentiful in S.Calif. We kept a few big shells. No you don't want muriatic acid on the pavers. I have also seen it discolor dark gel coats.

The foot plate will not increase in size. You want to get all of those off the boat before bottom paint. However I do recommend coats of epoxy to give an osmotic barrier before bottom painting. Not 100% necessary, but it will be a major step to stop osmotic blistering.
 
thanks! Now, if this supposed fishing town only had a lift! Considering taking off one bunk at a time, that should be interesting. Or buying our own lift :)
 
The 16 is light enough that using cribbing (or even concrete blocks with wood over, you can jack the boat up high enough to get between the bunks and the hull. Use safety precautions, and never put any body part between the boat and a bunk or support.
 
I have a 25’ cruiser that needs to have the bottom cleaned, prepped, and painted. This has not been done for several years - since I have owned the boat. This past two years the boat has been in the water. Any suggestions on what I might pay for a marine shop to do this?
 
Wild Blue":16a67816 said:
I have a 25’ cruiser that needs to have the bottom cleaned, prepped, and painted. This has not been done for several years - since I have owned the boat. This past two years the boat has been in the water. Any suggestions on what I might pay for a marine shop to do this?
Click to expand...

A lot will depend on if the hull was barrier coated previously and what kind of bottom paint it had on it--the boat did have bottom paint?? How much growth is on the bottom? I would say you are looking at a least several thousand dollars could be up to $4,000. Shipyard maintenance is billing at $150 to $180 an hour around here. Some independants will be as little as $80 an hour--but you pay for a professional. The paints will be several hundred dollars. What bottom paint are you going to put on.

It will be considerably cheaper if you can put an ablative paint on, over a hard coat (epoxy?) paine, and if the bottom was properly sanded, cleaned and then had 20 or so mils of barrier coat on before the last bottom paint job.
 
Wild Blue":30ujc26g said:
I have a 25’ cruiser that needs to have the bottom cleaned, prepped, and painted. This has not been done for several years - since I have owned the boat. This past two years the boat has been in the water. Any suggestions on what I might pay for a marine shop to do this?
Click to expand...

A lot will depend on if the hull was barrier coated previously and what kind of bottom paint it had on it--the boat did have bottom paint?? How much growth is on the bottom? I would say you are looking at a least several thousand dollars could be up to $4,000. Shipyard maintenance is billing at $150 to $180 an hour around here. Some independants will be as little as $80 an hour--but you pay for a professional. The paints will be several hundred dollars. What bottom paint are you going to put on.

It will be considerably cheaper if you can put an ablative paint on, over a hard coat (epoxy?) paine, and if the bottom was properly sanded, cleaned and then had 20 or so mils of barrier coat on before the last bottom paint job.
 
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