I found some, what I consider, large blisters on the bottom of my Catalina 22. It was fabricated in 78 and had been in the water at least 4 years before I got it. Paint is still good on the bottom. I have about 4-5 blisters that, after grinding, are anywhere from a pie plate to a turkey platter in size. I had to go through gelcoat and 2-3 layers of laminate. I plan on using woven and epoxy to fix them. Also fix any small blisters. That part should be easy. I plan on leaving as much of the gelcoat on afterwards and sand, scrape and/or chemically remove the anti-foul paint and dewax/clean. Then put epoxy finish over the entire bottom of boat up to boot line. Then paint with anti-foul paint. Does that sound like a good plan?
Repairing LARGE blisters
- Thread starter Nathan57
- Start date
With blisters that size I would think that hull is doomed. I hope you are sure that its only 2 or 3 layers of laminate, because that is actually pretty shallow, about as thick as 6 sheets of paper. You need to plan on allowing the hull to dry out for 8 to 12 weeks.
I hope you've read my resto thread, I did a blister repair on my hull. I had close to 140 total, but all were the average size of a dime, only a few about quarter size and all shallow. You should really consider inverting your hull for this job, trust me.
I hope you've read my resto thread, I did a blister repair on my hull. I had close to 140 total, but all were the average size of a dime, only a few about quarter size and all shallow. You should really consider inverting your hull for this job, trust me.
Yes, it was gelcoat, mat, woven, then mat. Have not noticed if it went deeper. May take one of the places and grind a little deeper and see if it is wet or has pooled water. checked them this morning after grinding 2 days ago and they seemed relatively dry. Didn't notice any seeping or weeping. What is the inverting you are talking about?
You really need to read my thread;
http://forums.catalina.sailboatowners.com/showthread.php?t=166613&page=7
Hull flipping and blister repair begins on page 7. Enjoy.
http://forums.catalina.sailboatowners.com/showthread.php?t=166613&page=7
Hull flipping and blister repair begins on page 7. Enjoy.
The hull is certainly not doomed, not even close. Its just going to take a lot of work. Just make sure that your repair incorporates the proper bevel ratio. (lay a straight edge over the blister (assuming you have it fully ground out) and measure the depth. a standard ratio for beveling is 12:1. if your blister is one inch deep (c'mon, its an example!!) you would need to bevel back the surrounding area such that it gradually meets the surrounding elevation 12 inches out from the repair.) and you will be fine. After beveling you will start layering in the mat ( or your choice of glass product, I like biax). Starting with a piece that roughly matches the dimensions of the deepest spot (this will be the smallest piece) you will add larger and larger pieces of mat until the last piece is the perfect fit for the hole and the thickness matches up perfectly with the surrounding area.... ahhh bliss.... too bad it never happens that way. once you are back to factory thickness you will have to sand/fill/fair the area to prepare it for topcoating. Lots of boats get holes in them or through cracks from hitting something and they are repaired this exact way. the excellent thing about fiberglass is that it can ALWAYS be fixed!
you also should not have to let the hull dry out if you have truly ground all of the damage out. It would not be a bad idea to let it sit (as Luke did) if you are unsure, but if all the damage is removed you should only have dry glass in there.
more food for thought, epoxy has excellent adhesive properties that would be very well suited to this repair, but you are limited on what you can topcoat with. it HAS to be an epoxy product. not a big deal, but something to keep in mind.
you also should not have to let the hull dry out if you have truly ground all of the damage out. It would not be a bad idea to let it sit (as Luke did) if you are unsure, but if all the damage is removed you should only have dry glass in there.
more food for thought, epoxy has excellent adhesive properties that would be very well suited to this repair, but you are limited on what you can topcoat with. it HAS to be an epoxy product. not a big deal, but something to keep in mind.
Thanks CloudDiver and Hawk232. I read the article CloudDiver and it is great, good info, but I don't have room or resources to turn boat over. Guess I will lay the glass the old fashion way -- downside down. I already have most of the places ground to 1:12 as Don Casey had suggested in his book. I am using epoxy to fix the hole the way you said Hawk232. Don had suggested not using Mat with the epoxy as the glue in mat may not be compatable with the epoxy, weakening it. Have either of you experienced that? Is the "new" mat more compatable? Is there a special mat? I would rather use more mat as it would take less time and trouble than a lot of layers of woven. Thanks guys
Take a look at the WEST epoxy web site, they have all kinds of information on proper blister repairs. But like Luke said, you'll need to allow the hull to dry out to properly repair them.
Don
Don
Update on my boat. I got all the blisters repaired using Hawk R1 epoxy and woven glass. As there was not a good fairing with the glass on the larger blisters and some smaller ones, I used the Interlux Watertight putty. That stuff is the greatest thing I have worked with. If you have gouges, holes whatever; the Watertight is the fix-all for boat problems.
Update on this project. CaptDon01, I haven't applied the barrier coating. I posted earlier some questions about using Pettit Protect instead of Interlux 2000e. I liked the 3 coats instead of 4-5. I am hoping I got enough to do at least the bottom of the boat. I have 2 gal and a quart which comes out to over 450 Sq ft coverage and, through calculations, will put 3 coats on my Catalina 22 which figures to be 420 sq ft total. Weather here in East Texas is fair enough but having lots of rain. May have to wait until early spring. Will use Pettit Unepoxy bottom paint on that.
Just remember, the more coats of the barrier coating, the better. No such thing as too much in my opinion. On my original C-22, after I performed the barrier coating on the bottom, I sanded and prepared the entire bilge areas and applied barrier coating on the inside also. It gave a nice hard grey surface that looked nice, and was easy to wipe clean. But the fumes took a toll on me..... I started looking for reasons to go stick my head in the bilge and do more painting!
I'll be heading across Texas probably this coming Sunday. Leaving on the first of my toy hauling trips across the country to our new home in Florida. Departing San Diego Saturday with the kayaks in tow and hoping to make El Paso the first day.
Don
I'll be heading across Texas probably this coming Sunday. Leaving on the first of my toy hauling trips across the country to our new home in Florida. Departing San Diego Saturday with the kayaks in tow and hoping to make El Paso the first day.
Don
CaptDon, I like the idea of the barrier coat inside the boat as well. How do you get it inside that area between the hull and the liner/floor? I have a small access hole but not big enough to get into that area. I have some leaks on the topside that are leaving about a pint or so of water in that area after a rain. Did take care of the major leak around the mast step. Will post pictures and process later. The mast step had twisted sometime and left a hole where the front bolt went into the deck. The plywood had rotted in that area of the deck. I cleaned out what I could and dryed it out pretty well. Didn't have 1/2 inch plywood to replace in between the surfaces of the deck. I have a good supply of Corain countertop material, so I cut chunks of that, used 3M 4200 on them and shoved then up in the space around where the step rests. Then filled the gaps, as best I could, with fiberglass cloth scraps saturated with epoxy. That area is solid as a board now. Most of my water is coming in around the windows so will reseal them.