Bow thruster installation pix

[Keith]

I finally got around to posting pix of my bow thruster installation, from beginning to end at http://www.flickr.com/photos/keith77/.
This is on a 1986 Krogen 42. I'll post pix later of the other various work done, mostly a peel/dry/relaminate of the entire lower hull. Warning: Please be sure to only look at the boat technical stuff, and ignore all the pictures of scantily clad women in the pool, etc. on the rest of the site. Yea, right!

[Phil Fill]

Keith so where are the bow thruster picture, I did not notice any? Which is OK because who want to look at dull old bow thrust pictures anyway? If you have other more those more interesting picture feel free to post them at any time. (-; I mean just because this a boat site there are other more interesting things. If you know what I mean?

[Keith]

<h1>Duh! The link in my last post...</h1>

[stevensibs]

Hi Keith, I am cutting my hole for the 8 1/2" fiberglass tunnel this weekend so I was interested in your thruster pics...but you've posted 488 pages on Flicker. Can you narrow it down for me?lol
Steve

[rochepoint]

Try this:

http://www.flickr.com/photos/keith77...7603383532093/

[Keith]

Well Mike beat me to it! Thanks!

[psneeld]

Originally Posted by Keith

I finally got around to posting pix of my bow thruster installation, from beginning to end at http://www.flickr.com/photos/keith77/.
This is on a 1986 Krogen 42. I'll post pix later of the other various work done, mostly a peel/dry/relaminate of the entire lower hull. Warning: Please be sure to only look at the boat technical stuff, and ignore all the pictures of scantily clad women in the pool, etc. on the rest of the site. Yea, right!

Getting ready to relaminate my hull after a major grind...would be very interested in any relsm photos/info.

Thank you...

Scott

[Keith]

I'll set up an album in here once I figure out this new software.

[stevensibs]

Keith, thanks for the photos. I am just about to cut the hole out for my thruster...I noticed in your pics that your hull looked completely peeled of gelcoat...did you peel the whole hull? I ask because I must deal with bad osmosis all over my hull and am going to Cranston RI tomorrow to look at the USA equivalent of the Gelplane made in the UK. This tool removes up to 3/32" of gelcoat in a single pass, 1 sq. foot in 20 seconds. That being said, how did you do yours?

[Keith]

That's what I did.Took everything off down to the first layer of woven, post-cured with the Hotvac system,then relaminated and barrier coated. Cost about $25k, but nary a blister since. That was about 8 years ago.

[stevensibs]

"then relaminated and barrier coated."
What do you mean by relaminated...more cloth? If so, what kind/weight? Biaxial mat? Vinylester resin?
Sorry for the machine gun questions but I have to do this right as you well know. I thought I mich just sand the bottom smooth as the blisters are only 1/32" deep and the hull is very dry, then barrier coat with Seahawk Epoxy barrier. 2 coats gives 8 mill thickness. But I am open to other options...

[Keith]

Here's the full report:

Well, now that Anastasia III is back in the water after about 5 months,
I can post the summary of work done and costs.

Boat: 1986 Krogen 42, hull #99. Had severe blistering when I purchased
her, and planned to do a hull peel and drying to cure this. After a lot
of research, I decided to use the HotVac system to dry the hull.
http://www.hotvac.com/. Seabrook Shipyard did all the work. This was
their first time using the HotVac system, so we all learned a lot. I am
very pleased with their work and the results.

Time: I took her into the yard on Oct. 21, 2002. They started peeling
the hull almost immediately, and started using the HotVac system around
November 15, 2002. While the HotVac folks said it would take a dwell
time of about 6 hrs at 100 degrees C to dry each section, we had to
operate at 80 degrees C because of the Airex PVC coring in my hull. It
took about 18 hrs. /section to dry the hull to acceptable levels. The
HotVac system uses three heat/vacuum pads at a time, each are about 2' x
3' or so. Several areas needed to have the application done 2 or three
times, and a few areas just wouldn't dry, so we had to grind out a few
places and re-fiberglass. The hull was finished drying sometime around
January 13, 2003, about two months. The pads were usually applied and
running 5-6 days a week, sometimes less if the weather didn't cooperate.
While the boat was in a shed, when warm fronts or rain would come
through, the hull would sweat and the pads couldn't get a seal.

We started relaminating new fiberglass on January 27, 2003. Started
applying the first barrier coat on February 24. 3rd. coat of barrier
were put on around Feb. 27. 1st. coat of anti-fouling put on around
March 8. New boot stripe painted around March 18. Final coat of
anti-fouling applied around March 20. A little touchup on bottom paint
on March 25 after lifting off the blocks onto the sled, then splashed on
March 26, a bit over 5 months after starting. I took a LOT of pictures
of all of this, and the automatic date stamp in the digital camera was
very useful, and allows me to give you these dates. I highly recommend
you use one of these for any major project you do.

After peeling and drying the hull, here is what we applied:

3 sessions of 1.5 oz. fiberglass mat with vinylester resin
2 coats Interprotect 1000 - High build epoxy primer
2 coats Interprotect 2000 - 2 part epoxy barrier coat
1 heavy sweep Interprotect VC tar2 - Watertight 2 part epoxy putty
3 coats Interprotect 2000 - 2 part epoxy barrier coat
2 coats antifouling - Petit Trinidad SR (4 gallons).

The relamination of new fiberglass was in addition to the bottom job,
and should be considered as an additional expense if you are doing
estimates. Labor was $7100 and materials were $3060. We had to do
this due to the amount of FG we ground off during the peel.

I prepped all the underwater metal except the prop with Petit's
underwater metal kit. This has a two-component acid etching primer
followed by two coats of a tie coat primer. I was disappointed with the performance of this stuff. The main and thruster props were prepped by the yard with Interlux 260R primer.

Costs:
After doing my hull, Seabrook Shipyard has set their pricing as follows:

Complete blister job including hull peel: $250/ft. – Sail, $300/ft. – Power.
Powerboats are a bit more expensive due to the more complicated hull
shape. However, if you have a trawler with a “sailboat” shaped hull,
they’ll probably charge you the “sail” price.

Use of the HotVac system to post cure (dry) the hull:
$200/day.
Estimated drying times based on a 40’ hull would be:
Solid hull (no coring) – 20 days.
Cored hulls – 40 days.
Different types of coring requires different drying times, so these are only
rough estimates.


My hull was a little less expensive, since it was their first time, and
we were at the bottom of the learning curve.

[psneeld]

I'm repairing all the ground out woven roving with 18 oz roving and where I ground off all the outer mat under the gel coat and shallow blisters I am covering the whole bottom with 6oz cloth and US Composites thin epoxy. Then 6 coats interprotect 2000.

I ground off by hand as they say it will dry the hull faster because you go deeper where the damage is.

[stevensibs]

Thanks Keith, I was hoping not to have to re-glass. *sigh*. I'm still going to try sanding first before I buy the Gelplane because the little dimples are really not deep, plus the hull is not cored, it's solid glass, very thick. Do you have the link to your pics of the bottom job if I may be so bold?
Thanks again for your time.

[Keith]

I just put an album under my profile with a lot of pictures from that bottom peel job. I guess you click on my name then look for picture albums. It's the only one there.

[Ocean Breeze NL]

Yep, great pictures, lots of hard work Keith. I had the same thing done to mine last fall..

Originally Posted by Keith

I just put an album under my profile with a lot of pictures from that bottom peel job. I guess you click on my name then look for picture albums. It's the only one there.

[psneeld]

Here's what came off my bottom. 6 layers of roving and 6 mat in some spots. Some spots so easy you could strip a lot by hand.
Blisters aren't ANY indicator you may be having larger problems with hydrolysis. Without coring or deep grinding you will never know. A highly recommended surveyor with a moisture meter and tapping hammed didn't catch this (but to be fair you can't without a dry boat and grinding though bottom paint and gel to use the moisture meter)