Springtime shock

rpmerrill

Well-known member
Joined
Feb 5, 2016
Messages
608
Fluid Motion Model
C-28
Vessel Name
BAY RANGER
When my boat was surveyed last spring, the surveyor pointed out some "cosmetic pockmarking" on the hull in a band just below the waterline. He chipped and picked at a couple and told me that they were nothing to worry about. "Not blisters - Ranger Tugs are vinyl-ester." He said they were cosmetic and could be faired in with filler next time the bottom was painted. Is my boat vinyl-ester? Is it true that V-E doesn't blister?

A photo is in my album. These pockmarks are about the size of a pencil eraser or smaller, but appear to be fairly deep.

Today at my marina, talking with the boss about bottom painting before I go back in the water. He says that they ARE blisters and the entire hull needs to be sanded thoroughly, then three coats of primer, then the expensive bottom paint. All to the tune of almost $2500. (I don't know about anywhere else, but in my neighborhood, they never write anything down or give a legitimate quote or work schedule). The mechanic suggested just sanding the sides where the pockmarks are and prime and seal that. Then apply the new bottom paint. I don't think I have a real number on that but it is bound to save a lot.

Looking for a lot of comments here... let the games begin.
Thanks all,
PS: After I posted the photo, I looked at it closely. This photo was taken during the survey before I bought the boat. Notice that the areas around the pockmarks is sort of shiny.... kind of like a sealer or touch-up was applied at some prior time. I was at the survey short-haul. The hull was slimy and dirty. They pressure washed it so we could inspect, but the shiny areas around the marks make me a little suspicious.
 
R.P.,
When we bought our boat if I remember correctly. We had two coats of epoxy barrier paint applied and then a couple coats of Mar Pro Super Gold bottom paint by a contractor who works with Wefings out of Eastpoint Florida. Your marine guy is in the same ballpark as we paid. That is was without having to deal with the blisters. As a lot of people have said vinyl ester does not have blistering issues, strangely enough most recommend the epoxy barrier coats no the less before picking out a bottom paint to apply. I'm thinking the $2500 dollar figure for your type of complete bottom paint isn't out of line. There are no Brinks trucks in heaven and if your yard doing the work has a good reputation I'd vote for doing it right.
 
Weird! Out of curiosity I searched the internet and found some interesting reading.

This first one discusses in some detail on how osmosis can cause blistering. However the pictures do show blisters and not pockmarks. Perhaps the pockmarks appeared after vigorous hull cleaning which removed the outer cover of the blister?

http://www.yachtpaint.com/LiteratureCen ... ng_pro.pdf

The next two are from forums and the pictured pockmarks look similar. However nothing conclusive here.

http://www.sailnet.com/forums/gear-main ... -hull.html

https://forums.sailboatowners.com/index ... om.176297/
 
Thanks Scuffy, I think. Ha.
You too Scuba Too. The idea of freezing has merit... if the boat was in the water and there was freezing at the surface, along the waterline it could show up there. Still and all, I don't like the idea of all those things being blisters.

Keep the comments coming.
 
I'm shocked that if this is osmosis its being reported in such a young boat! it normally takes years of being left in the water for this to happen.

are we sure its not just a failed layup and that resin didnt flow into those areas of the glass fiber at build time?

also note the internet is filled with misinformation on blisters and osmosis!
 
Just speculating here but the photos look like this is and old problem that has a previous treatment. If these were new pockmarks there wouldn't be bottom paint in the holes. From your photos it doesn't look like there has been any new degradation since the previous paint was applied. I would leave it alone for another season and see if there are any changes. I guess I agree with your surveyor. Cosmetic at this point. Just my thoughts.
 
We absolutely use a vinylester resin on the hull but this doesn't mean it will never blister. I tell every owner that the boat should not be left unpainted for more than 30 days in the water at a time. It is very rare but have seen it before. The cost to bottom paint the boat is absolutely close to what someone would charge. Many in the south use a barrier coat to protect but all of the boats up in the NW do not use a barrier coat. I have never seen or heard of a blister on any of our boats that have been painted with or without a barrier coat.

Thank you for sharing!
 
Not longer than 30 days without paint? Just curious about people with boats on trailer who have done for instance the great loop which I would assume takes longer than 30 days, do you have bottom paint and does it hold up on the trailer?
 
We've done 2-3 months on the Inside Passage many times, and kept New Moon on her trailer over the winter. After every summer cruise I would spend many tedious days cleaning barnacles etc off the unpainted hull. After the first few weeks of each cruise it was clear that performance was increasingly degraded with more time on the water.

In 2006 I painted with Pettit Hydrocoat (water based ablative). It worked well without even a touchup for several years. Added new coats on the sides, chines, and transom, and it worked well for several more years.
 
an old yard mechanic showed me his test for osmotic blistering: 1) get a pin. 2) find a big blister. 3) pop pin into the blister. if liquid coming out smells like vinegar (aka acetic acid) it's osmotic blistering. 4) he actually tasted it to confirm.

i did this test -- including step 4 --- on a boat a friend was thinking of buying. blisters some as big as quarters all over the bottom. vinegar smell and taste very noticeable. he negotiated the price down by 3K to take care of the cost of soda blast sanding the bottom down , applying a barrier coat then applying 2 coats of good quality bottom paint.
 
stwendl":2byq3o87 said:
Not longer than 30 days without paint? Just curious about people with boats on trailer who have done for instance the great loop which I would assume takes longer than 30 days, do you have bottom paint and does it hold up on the trailer?

All of our boats have had bottom paint. I don't see a downside. If you plan to trailer or have your boat out of the water, you'll want to use a bottom paint that remains effective when taken out of the water. We trailered our C-Dory coast to coast on multiple occasions, no issue with the paint wearing (we use bunk slicks over the carpeted bunks). No issue going from salt water to fresh, and back.

In the southern Gulf area, the bottom would be a mess within 3 weeks without bottom paint, even if the boat is used regularly.
 
Andrew Custis":ehs7vapv said:
We absolutely use a vinylester resin on the hull but this doesn't mean it will never blister. I tell every owner that the boat should not be left unpainted for more than 30 days in the water at a time. It is very rare but have seen it before. The cost to bottom paint the boat is absolutely close to what someone would charge. Many in the south use a barrier coat to protect but all of the boats up in the NW do not use a barrier coat. I have never seen or heard of a blister on any of our boats that have been painted with or without a barrier coat.

Thank you for sharing!

Hi Andrew,

Is the concern regarding boats without bottom paint in the water in excess of 30 days due to marine fouling or damage to the untreated bottom?

Thanks,
Gary
 
Hey there Gary.

It can actually be both. Vinylester certainly prevents blisters more than polyester but doesn't eliminate the possibility. Sometimes freshwater can actually be worse than saltwater.
 
Another bottom paint question to all of you - we took our boat out of the water in October, power washed, and placed on trailer. The paint looks good. It will go back in the water in June. Plan to repeat same after this years boating season, June to October. How long can the bottom paint last when OUT of the water and be effective? Do you stay with same paint as applied by Ranger Tug factory? Do we need to reapply paint before the boat goes in this year when bottom looks clean, smooth, paint looks good?
 
Don't know about your particular bottom paint, but my Pettit Hydrocoat water-based ablative lasted through 9 summers, out of the water 8 winters for 8-9 months at a time, before it seemed necessary to put another coat on sides/chines and transom.
 
There are paints that are made to last out of the water and those that must stay immersed. I believe Ranger uses a paint that is the former since the boats are trailerable and it is expected they will spend time out of the water. I'm not sure what they use though. We have a Ranger applied bottom paint and pull out for 6 mos. every year. So far so good after three years. I probably will repair in a year or two depending how it looks.
 
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