I hate blisters

Justinf89 · Post by **Justinf89** » Mon Jun 09, 2008 6:11 pm

Well, since everybody has been showing off lately, I'll show off how badly my baby is blistered. Here is some before and after pictures of the sandblasting process. I started to sand and got about ten minutes into it and you can figure the rest. The sandblasting job was $30 a foot so I went for it. http://s295.photobucket.com/albums/mm13 ... 9/Bertram/ Whomever tried to fix the blisters before patched them and even put on a barrier coat but it looks like they did it wrong because there sure are a ton. I decided to go to town and never realized that there were that many! In the end, I'll be happy I went the extra mile. I also finished up the topside below the rub rail with 3m compound but haven't put wax on it yet. I can't decide if I want to go over it again to give it that extra shine. Also, I had a question about the strange bronze things under the hull on both sides. It's about 3" wide and 12" long and appears to do nothing! Just wondering if anyone knew what it did Here's the pic: [img]http://i295.photobucket.com/albums/mm13 ... C00428.jpg[/img] I didn't grind the one on the port side clean: [img]http://i295.photobucket.com/albums/mm13 ... C00435.jpg[/img] Also, my nibral props are pitted, especially on the backsides. The nuts holding the props on were soft when I took them off and crumbled in my hand but I can't get the props off, even with a 3 tooth puller. Is there a procedure on how to get them off because I would like to have them tuned. Thanks guys!

franklyprice · Post by **franklyprice** » Mon Jun 09, 2008 7:15 pm

Justin, Those plates are grounding or bondng plates. They can be attached to the bonding system or for a SSB radio or even a lightning ground. The prop puller that looks like a large nut cracker will put more force on the props due to leverage, it's what I use. If they are stubborn after that , use a cheater to get it really tight and then a few light raps on the prop hub should do it. The trick is to get get the prop vibrating with the pressure on and then she'll pop off. Not sure what size props you have but mine are available cheap,1 1/2 " 24X 24"(approx) tuned recently by Accutech.

lobsta1 · Post by **lobsta1** » Mon Jun 09, 2008 9:14 pm

Justin, I believe this is what Frank is referring to. You can often borrow them from a prop shop. Al http://www.mindermanmarine.com/prop_puller.htm

franklyprice · Post by **franklyprice** » Tue Jun 10, 2008 4:13 am

That's the one. Way more pulling power than the type with just bolts to tighten.

buzzk · Post by **buzzk** » Tue Jun 10, 2008 6:37 am

Are you sure that some of the problem wasn't caused by the sand blasting? Or if the bottom was sand blasted wrong before you owned the boat.What kind of material did they use? Soda, nut shells or sand. Every time I have had the bottom paint taken down to the glass I had them sand it off. Not very often do you see Bertrams with blisters.It lookd like you will have the problem fixed now. Buzz

Justinf89 · Post by **Justinf89** » Fri Jun 13, 2008 1:20 pm

Sorry guys for the slow response but these blisters suck, I grind them out and the water keeps coming back. I cant wait all year for them to dry! I'm going to ask the boatyard monday if they by chance have a puller. My props seem to be undersized, only 20x17 but it tops out at 28 knots with pcm 454's. I don't even know the horsepower on them. Thanks for the help guys, hopefully I can get my small props off and see if the pits in them are alright. Oh and by the way, don't ever use a three tooth 'gear puller' as I call it, I indented the prop hub on the edges.

Rob_C · Post by **Rob_C** » Mon Jun 16, 2008 9:28 pm

So you are the guy that bought "Foggy Bottom". That boat had been for sale for at least 6 years so I figured there must be some issues. I considered buying her but once I saw all of those blisters on the bottom when they had it hauled out in Poquoson a couple of years back I decided to keep looking.

smanni · Post by **smanni** » Tue Jun 17, 2008 4:18 am

Interesting - (2) grounding plates. Usually there is only one. I think Dynaplate - or Dyna....something makes them. I had them on my old boat but not on this one.

Justinf89 · Post by **Justinf89** » Tue Jun 17, 2008 4:21 am

Yep I'm that guy and yes there were a lot of little problems that are almost all fixed now! I couldn't let a 28k bertram pass. It was the best decision I had ever made!

smanni · Post by **smanni** » Tue Jun 17, 2008 4:54 am

Nice - 28k for a boat that if you redo it and treat it right - will last you forever. NICE.

buzzk · Post by **buzzk** » Tue Jun 17, 2008 5:43 am

Good deal on the boat. Is there anyway you can dry the bottom out besides just waiting around? I know that it has to be competely dry before sealing the bottom. Buzz

Grady Smith · Post by **Grady Smith** » Tue Jun 17, 2008 6:32 am

Hi Justin, My boat had blisters. Similar to yours. Didn't faze me when I was deciding to purchase. We sandblasted them. I actually rent that equipment so I took a blaster down to the boat with very fine sand. If you hit the blister with the tungstan carbide nozzle tip which holds a tigher pattern than a ceramic tip and go round and round in a very small circle pattern and gradually enlarging the circular patten you can actually watch the blister change color as the sand eats into and removes the wetted area and you are left with only dry. Remove no more than you have to to get to the lighter color. Stay out of as much gelcoat as you can. The wet area is darker. It takes literally 10-30 seconds to do each blister this way. Use a big ass fan behind you to blow the fiberglass away from you. This is easy to do if you get a squirrel cage type floor type fan and point it directly at the blister. This helps almost totally avoid the itch. Don't do this when others are around in the yard. Or put up a plastic tent. I got a bit of grief from a couple of guys that said they had dust on their boats and had just washed them but the yard had told me I could do the blasting. Once this is done you HAVE to wait for it to dry out. You can use fans to stir the air underneath....we are talking awhile......I didn't use anything underneath as I recall but we made sure there was absolutely no water inside the boat......... I think I might have had a a fan inside and we may have put a dehumidifier inside the boat to suck down the moisture level inside to try and "help" the drying process. The drying occurs from both sides inside and outside I think. My yard said 3 months.......we waited 3 months. They ran a moisture meter on it every 2 weeks until it was "dry". It won't be completely dry but the moisture level will be down to a level that's considered "dry". From that point I had a pro do the repair part.......with the micro plate barrier coat everybody uses......you probably know what I am talking about. He used dense filler......I can't remember exactly.......to fair the holes....the 2 coats of the micro stuff.....sorry to be vague. It was 4-5 yrs ago. My boat just went back in the water 4-5 months ago so don't know how it will hold up but I am confident there will be no further problems. I am going to pull the boat about 2 months a year to help prevent more. I think it may help to dry the hull a bit once a year.....but who knows.......hope some of this helps...... Grady

IRGuy · Post by **IRGuy** » Tue Jun 17, 2008 6:40 am

When I was considering the purchase of "Phoenix" I naturally had a surveyor do a full hull and systems survey.. When we had her hauled there were lots of small blisters (between dime and quarter sized) all over the bottom. My surveyor, who I trust completely, said that he would not try to repair them.. and that a lot of owners caused themselves more problems by having the bottom stripped and recoated than if they had left it alone. Mind you.. he was talking about small blisters.. I don't know if he would have the same opinion if the blisters were large. His comment was that southern boats are not hauled for the winter, and with my boat being wet for 25 years except for a few days here and there the presence of blisters is no surprise to him, and they should not present a problem.

Justinf89 · Post by **Justinf89** » Tue Jun 17, 2008 8:51 am

When I had my survey done, he actually said to pop the blisters and paint right over them. I couldn't believe it so I did my own research and sure enough, that was the complete opposite thing to do. As for most of the blisters, a grinder and a 36 grit flapper disk worked wonders in getting most of the water out. I waited about a day on about 3/4 of the blisters and filled them in with 3m filler. Some of the spots I have ground out are not very deep as I'm afraid to grind too deep, but I've ground out at least 12" in diameter and there's still water oozing out. I can't imagine how long it would actually take so I think I've come to the decision to just get them mostly dry with a fan, since it's 90 degrees most days, and fill them in and hope for the best. Of course, I'll put 3-4 coats of interlux barrier coat and micron extra bottom paint and get out tuna fishing! Too bad the gulf stream is over 60 miles right now and gas motors doesn't help! Thanks guys for all the input.

Grady Smith · Post by **Grady Smith** » Tue Jun 17, 2008 9:06 am

Justin, That 3M filler is possibly going to trap the moisture and that's not good......I would ease over to Bertram 31 and ask Capt Pat for his advice which will be spot on...... Grady