BLISTERS

[jeff everson]

im looking for helpful input so no hindsight please .i put my boat in for 3 weeks at a fresh water marina took it out to get engine tuned up/.. no blisters ..put it back in 4 ( 6) weeks saving up money to bottom paint if i liked the marina enviroment .took it out this weekend and EVERY SQUARE INCH LEFT UNDER WATER HAS BLISTERS LITTLE PIMPLE TYPES ??///i never thought in my right mind my boat would look like this but now the damage is done...my plan is to sand down the bottom with 80 grit and release the water and let it dry out the delima is that the epoxy primer suggest 5 coats of paint .i do not have that kind of money.im barely have enough to put the 100. into it for the one thin coat and then bottom paint i already had bought 1 gallon last week figuring it would help keep the alge off any helpfull suggestions on how to and what to do would be greatly appreciated those who are wanting to email me if you cant afford this you shouldnt own a boat please keep those thoughts to yourself i still hadnt made up my mind about keeping it at the marina it only cost 45 .a mth but now im looking at pulling it out at christmas when my rent is due again. or just letting the marina slip go i had in the past usually only put in for a 3 day weekend

[TAW02]

Hi Jeff;

I pulled my M out of the marina after about 3 weeks for cleaning. The algae is ferrocious in the summertime. I noticed many blisters on my starboard rudder ... and unfortunately a few on my bottomside. I have slip number 20 facing Crabby Bill's. I am more often vacant than I am in. Mainly because I prefer not to use bottom paint. The price to pay for that is, you leave the M on the hard more often than in the water.

Yes 6 weeks is a good length of time to leave raw fiberglass(with/without gelcoat) submerged. I would recommend an ablative bottom paint if your plans are to slip that long or longer.

In the meantime Jeff, let'er dry out for a few weeks before making a final assesment. 'What goes in will go out', and you will see many of those blisters disappear. Mine does. You just have to know your limatations. And thus, a lot of work can be saved. That is, before you put a lot of time refinishing a surface that may not require it. A simple prep and bottom paint will do the trick.

And by the way ... who said you have to do 5 coats of anything? If you feel that is what it takes go for it ... but do it a bit at time and as budgets allow. Enjoy the in between slips ... after all she's gonna outlive us both

Big T

[daydreamerbob]

If you let it sit for a week or so - you may not need to sand - mine was out for 3 and the blisters all but disappeared before putting on a barrier coat. I believe my dealer rolled on 2 gallons all at once - problem fixed. my very fast 08 M is in fresh water most of the time - it is a bit slower now as the barrier coat was molasses white -

"when you walk into a 3rd grade classroom - how can you tell which kids will grow up to skipper blue M's from those that will grow up to skipper white M's?"

"Easy the White M skippers are bigger - they are 18 years old"

[daydreamerbob]

The white M skipper was in his fourth year as a college freshman; one day in American History Class the professor asked the class to describe the significance of Roe vs. Wade - the white M skipper was tremendously excited as he was certain he knew how to answer - the professor called on him - "yes Poindexter" -

Poindexter gave his answer - "Roe versus Wade was the decision George Washington had to make before he crossed the Delaware"

Of course we all know that both options presented by Poindexter would have been faster than Sailing a White M...

[jeff everson]

THANKS FOR THE INFO,,,I GET THERES A CHANCH THEY MAY COME OUT ??//WHEN I CALLED THE MAC FACTORY YESTERDAY ALL I WAS POLITLY TOLD IS THE MANUF RECCOMENDS A EPOXY BARRIER PRIMER FIRST THEN A BOTTOM COAT.I BOUGHT 1 GALLON OF WEST MARINE BLUE LAST WEEK WHEN IT WAS ON SALE JUST WANTED TO PUT A THIN COAT ON TO HELP KEEP THE ALGE OFF.I SANDED A 2X3 INCH AREA ON THE BOTTOM LAST NIGHT AND THEN CAREFULLY POKED A SMALL HOLE IN ONE OF THE BUBBLES (NO WATER)IT APPEARS IST JUST THE TOP GEL COAT. ANY MORE SUGGESTIONS WILL BE APPRECIATED

[TAW02]

THANKS FOR THE INFO,,,I GET THERES A CHANCH THEY MAY COME OUT ??//WHEN I CALLED THE MAC FACTORY YESTERDAY ALL I WAS POLITLY TOLD IS THE MANUF RECCOMENDS A EPOXY BARRIER PRIMER FIRST THEN A BOTTOM COAT.I BOUGHT 1 GALLON OF WEST MARINE BLUE LAST WEEK WHEN IT WAS ON SALE JUST WANTED TO PUT A THIN COAT ON TO HELP KEEP THE ALGE OFF.I SANDED A 2X3 INCH AREA ON THE BOTTOM LAST NIGHT AND THEN CAREFULLY POKED A SMALL HOLE IN ONE OF THE BUBBLES (NO WATER)IT APPEARS IST JUST THE TOP GEL COAT. ANY MORE SUGGESTIONS WILL BE APPRECIATED

Yes the blisters will go away. Then come back after another 6 weeks in the slip. This happens over and over a few times at least I am told. Mine have disapeared and so I will be dropping her back into slip 20 again for a few more weekends.

What causes them? I have been told by experts in the field that it happens when epoxy resins are mix with hardner. With gelcoat that is shot on with a gun, the mix is measured through an orfice and drafted in with the resin as it is blown into the mold. Problem is, if the hardner is not metered and mixed properly with the resin it will either have a slow reaction or a too fast reaction resulting in a 'bad cure'. A too-fast cure can cause hairline cracks while too-slow can result in blistering thru water osmosis with the chemical reactance of the hardner(still active) in the resin molecule. When the glass is allowed to fully dry, surface tension will gradually return and the pimples or blisters will disappear.

So ..... I have to assume (my guess) is that this slow curing will eventually stabilize by the year 2050 or so and we will be able to permanently slip our boats without the worry of getting blisters.

So Jeff, if you undertake this job of epoxy bottomcoating ... yes, I would do a small patch at a time and in the meantime, still taker her out and have fun. Who says you have to have it all done before you splash her in the water? Besides once in the water no one will notice a partial bottom job

As for me ... I am too old to worry about all this maintenance. That is why I bought the M. (Less maintenance) over any sailboat on the market. Work subtracts from PLAY. And I intend to enjoy her and if she shows the scars of having fun, so will I

The next owner will have his/her work cut out for them

[Russ]

THANKS FOR THE INFO,,,I GET THERES A CHANCH THEY MAY COME OUT ??//WHEN I CALLED THE MAC FACTORY YESTERDAY ALL I WAS POLITLY TOLD IS THE MANUF RECCOMENDS A EPOXY BARRIER PRIMER FIRST THEN A BOTTOM COAT.

That is a polite way of saying, "It's not under warranty". It kind of hacks me off because it's clearly poor QC with the gelcoat. What other manufacturer forces you to paint your bottom to prevent blisters?
I have blisters on my 08 M and let them dry out over this past winter and most went away. The rest I can't see from the cockpit and I haven't noticed any decrease in performance. I also used Aurora bottom wax this season and the bottom came clean pretty easy compared to the cemented on algae last year.

I wouldn't do anything too quickly and if you're pulling her for the winter, wait until spring to do any bottom work.

--Russ

[Divecoz]

done

[Derrick]

I barrier and bottom coated my 07M when it was new before it hit the water. I left about a 1.5" white stripe below the black boot stripe for appearence reasons. Becasue of the M being bow heavy, a 5 foot section of the white stripe at the bow Is slightly under water. I had no problems the first year (in water from mid-may to mid October). The second year (last summer) when I pulled the boat in mid october I had the same tiny blisters on the 5 foot stripe that goes under water.

I was not able to deal with the blisters in time for winter. Boat sat all winter. Last spring I used a small palm sander with 220 grit paper and lightly sanded all the blisters out. None had water in them and they did not change over the winter. I ended up sanding the whole white stripe barrier and bottom /barrier coating all the way up to the boot stripe.

[Duane Dunn, Allegro]

Actually, I can't think of any manufacturer of a fiberglass sailboat that lives in the water all the time who doesn't recommend, require, and usually actually install bottom paint. To think you can leave bare fiberglass and gel coat in the water for long periods of time without problems is ignoring the long history of all FRP boats.

I also don't know that this rough gel coat issue is really 'blisters' in the classic sense. A blister results when water penetrates the gel coat due to osmotic pressure and collects in the laminate behind the gel coat. This results in the classic blister, usually much larger, that contains water and must be opened, dried, and then filled before it is finally re-coated with bottom paint. This seems to be problem that is not as serious.

This problem may be worse on a Mac which no doubt is built using the cheapest gel coat available on the market. I'm sure all the Mac factory uses is inexpensive polyester resin which historically has had more blister problems than the newer vinylester and epoxy resins. All the best, most blister resistant, and most expensive boats these days are built with epoxy resins of which I'm sure there is none of in a Mac. That's why the epoxy barrier coat is an important (and expensive) component of any Mac bottom job.

Blisters are nothing new in the fiberglass boat world and are certainly not limited to Macs. It's only recently with the availability of better resins that even the high priced boats cover blisters in their warranties.

I must say I also wonder what is happening inside the ballast tanks of those who leave their boats in the water with full tanks all the time. The tank isn't even protected by a gel coat layer. No way to put an epoxy barrier coat there.

[Kelly Hanson East]

I must say I also wonder what is happening inside the ballast tanks of those who leave their boats in the water with full tanks all the time. The tank isn't even protected by a gel coat layer. No way to put an epoxy barrier coat there.

They are honestly a resale issue only for our boats. If you are going to slip full time, or may want to resell in the next 5 years, then bottom coat.

If you trailer sail or mast up slip sail and plan on leaving your boat to your heirs....ymmv

[jeff everson]

thanks for the xtra input,since florida is suppose to be getting cooler (better sailing weather )i plan on putting it back in the marina in a coupple of weeks ,i have noticed that in some areas the blisters are already getting smaller if they dont come all the way out i still will only have to sand and paint once ..

[TAW02]

But by all means do have fun with your

http://s947.photobucket.com/albums/ad31 ... Lounge.flv