Catalina 34

General Activities => Main Message Board => Topic started by: Footloose on April 19, 2016, 05:28:22 AM

Title: Need Input on Barrier Coat
Post by: Footloose on April 19, 2016, 05:28:22 AM
Footloose is being soda blasted this week.  The plan is to apply VC17.  I would like some input on barrier coating.  There has never been any barrier coat on this boat.  I am very sure that no prep was ever done before the PO applied the initial bottom paint as where it has peeled the gel coat shines.  I know that I need to apply at least one coat of Interprotect as a primer.  Would others go ahead and apply a full barrier coating of 3-4 more coats or just the one?  I should add that the boat has no blisters and is on the hard more than in the water due to the short northern sailing season and is in fresh water.  Thanks!
Title: Re: Need Input on Barrier Coat
Post by: Jim Hardesty on April 19, 2016, 06:22:01 AM
I would do the full barrier coat.  Prep is the most work and that's done. I think the extra time/money would be a small addition to the overall project.  But then it's probably not necessary.  Perhaps a selling point when you sell the boat.
Jim
Title: Re: Need Input on Barrier Coat
Post by: KWKloeber on April 19, 2016, 08:54:41 AM
Recommend a full barrier coat, better safe than sorry. 
I took down the hull (2nd owner '84 C30) and redid the bottom down to substrate that had obviously blistered and the yard's repair job was crap.  I sprayed 8 light coats of VC Tar to get the mil thickness, followed by VC-17.  Never an issue again once it's done.  Naturally VC Tar isn't available anymore - it worked too well.

ken
Title: Re: Need Input on Barrier Coat
Post by: Jim Hardesty on April 19, 2016, 11:05:44 AM
One other thought.  If your barrier and bottom paint isn't well (an inch or two) above the water.  Now is the time to move it.  On the first boat I barrier coated I left the water line as was (above the water but not by much) and got some "splash blisters" on the gelcoat below the boot stripe.  Not a big deal but would have been an easy thing to avoid if I had known.
Jim
Title: Re: Need Input on Barrier Coat
Post by: Miles Henderson on April 22, 2016, 06:41:59 PM
Everyone I have spoken with regarding this matter recommends several coats of Interprotect 2000E.  I put on seven coats.  If you plan on keeping the boat it will be worth it.  My boat was covered by VC Tar, then covered by VC 17.  The VC Tar got old (12 years) and then became brittle and started to peel.  Had it soda blasted to the gel coat.  I am quite certain one to two coats of 2000E will not provide the seal you want.  The paint is good; but, not that good.  Read the manufacturer's recommendations.  I put on two coats and could then observe the natural peaks and valleys in the surface.  I did a light sand with a cross-board to highlight the high spots, then outlined the low spots with a black magic marker and then filled in low spots with 3 to four coats of 2000E.  By the way, after several coats of 2000E, it will start to "orange peel".  That is the surface of the paint will start to become rough and resemble the skin of an orange.  If you want to get rid of this rougher surface (the get a racing finish), you can have one person put on the paint with a roller and then immediately have the other person follow up with a plastic resin spreader (it will take the excess paint and spread it among the valleys of the orange peel).  Good luck. Mine has been on seven years and it's like brand new.  Good luck. :thumb:
Title: Re: Need Input on Barrier Coat
Post by: Ron Hill on April 27, 2016, 02:52:17 PM
Dave : You had some kind of a "barrier" to protect your gelcoat.  The barrier might have been the just the bottom paint, but it acted as a barrier and prevented the osmosis of water thru the gelcoat.

I'd say you are lucky that the paint didn't peel off the smooth shiny gelcoat. 
Like the others said - go for Interlux barrier coats!

My thoughts

Title: Re: Need Input on Barrier Coat
Post by: Footloose on May 16, 2016, 11:33:48 AM
In case anyone cares, I went for the full barrier coat.  When the old paint was stripped off there were several blisters that I had to repair.  FWIW-it takes a gallon of Interprotect per coat and 2 1/2 qts of VC17 per coat.  Glad this job is almost done.  Just the area under the pads to do at launch.
Title: Re: Need Input on Barrier Coat
Post by: Footloose on October 21, 2016, 05:25:07 AM
FWIW-The boat is on the hard for the winter.  No blisters and the bottom was very clean.  The VC17 certainly improved boat speed.  I first noticed it after launch.  I revved the throttle to my usual RPM.  I looked at the knot meter and noticed that I was going 1.5 knots faster than usual.  My first reaction  was to recalibrate the knot meter, but the GPS also said the same.  Also noticed that the boat did not slow as quickly when coming in to dock, which made for some tension the first couple times.  Very happy.  Thanks for the advice.
Title: Re: Need Input on Barrier Coat
Post by: KWKloeber on October 24, 2016, 07:07:05 PM

Dave, did you burnish the VC-17, or just splash as-is?

-kk
Title: Re: Need Input on Barrier Coat
Post by: Footloose on October 25, 2016, 04:29:33 AM
Just splashed as is.  It was getting to be a long project as a couple repairs had to be done to the bottom.  These were covered by the old bottom paint.  There was cracking around the skeg and I had to fair out the keel.  Also has the start of a smile.  Nothing horrendous but it all takes time.  If time allows next spring I may burnish it, but since I crew for someone else and don't race this boat, it isn't a priority.  I am considering doing Ron's rudder modification next spring, as this has finally made it to the top of the list.  The admiral is getting tired of rounding up.  Frankly, I am also!
Title: Re: Need Input on Barrier Coat
Post by: Ken Juul on October 25, 2016, 05:51:41 AM
The mod works great.  But before you do make sure your post is in good shape.  I had alot of corrosion around the lower bearing.  You are in fresh water, so probably ok.
Title: Re: Need Input on Barrier Coat
Post by: sailaway on October 27, 2016, 10:51:31 AM
Best way to put VC-17 is with a squirt bottle. Empty dawn soap bottle any thing. then squirt the VC-17 on the paint roller. VC-17 in a paint tray will evaporate fast. I can almost do my boat with 2 cans. I even keep the left over for pads or the next year. Charlie
Title: Re: Need Input on Barrier Coat
Post by: KWKloeber on October 27, 2016, 01:55:23 PM
Very ingenious!

Of course, it's only solvernt that evaporates if it's in a tray, so you can easily reconstitute it. 
But it seems a waste to paint the tray with copper, when you can apply it directly onto the bottom. 

-kk
Title: Re: Need Input on Barrier Coat
Post by: Footloose on October 28, 2016, 05:36:27 AM
I made a squirt bottle out of a clean 1 liter soda bottle.  I drilled a small hole in the cap.  A spare cap seals the deal on any left overs.
Title: Re: Need Input on Barrier Coat
Post by: KWKloeber on October 28, 2016, 06:55:55 AM
Quote from: Footloose on October 28, 2016, 05:36:27 AM
I made a squirt bottle out of a clean 1 liter soda bottle.  I drilled a small hole in the cap.  A spare cap seals the deal on any left overs.

Great ideas.  I have half a drawer full of these kinds of caps I've saved "just because someday" I might need them.  I think I found another use for them (besides on the top of my bottles of Collinite Cleaner and Wax when applying.)

(http://cdn4.explainthatstuff.com/poppet-valve-drinks-bottle.jpg)

-kk
Title: Re: Need Input on Barrier Coat
Post by: Footloose on November 03, 2016, 05:36:26 PM
Has anyone that has done the rudder modification added to the forward edge to keep the rudder balanced?  If so, how much did you add?  I am contemplating doing this to keep the steering for needing too much force, but if too much is added it will make it difficult to control.
Title: Re: Need Input on Barrier Coat
Post by: Stu Jackson on November 11, 2016, 04:47:55 AM
Quote from: Footloose on November 03, 2016, 05:36:26 PM
Has anyone that has done the rudder modification added to the forward edge to keep the rudder balanced?  If so, how much did you add?  I am contemplating doing this to keep the steering for needing too much force, but if too much is added it will make it difficult to control.

Dave,

Try this:  http://www.c34.org/projects/projects-rudder-modification.htm (http://www.c34.org/projects/projects-rudder-modification.htm)

Also go to the May 1999 TNOs for the original article that Ron wrote.
Title: Re: Need Input on Barrier Coat
Post by: Footloose on November 11, 2016, 11:46:40 AM
Thanks Stu.  I have read those write ups and they are very helpful.  What I am considering, is adding an inch or so to the leading edge to balance the steering.  By putting some surface area in front of the post it will decrease the force needed to steer with the added surface behind the post.  I fly radio control planes and this is often done with large control surfaces.  I may just be overthinking the whole thing. :donno: