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Discussion Starter · #1 ·
Ok just redone my floor in my 1977 sanger and now I have a nasty crack on the chine right under passenger seat. Fixxed temp. over 4th weekend to get me going now have a spot just in front of repaired spot.WTF????
 

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Discussion Starter · #6 ·
I relayered fiberglass in the whole bottom of hull whenever I had the floor out and could not see anything bad in this area whenever I had sanded to get ready for new glass.During the 4th weekend on the temp. repair I sanded out the crack good and along the edges of the crack then found some Devcon H2 hold 2 part epoxy that is flexible and waterproof and sealed up crack with it. That worked great but after running in some rough water again before I loaded back up it had a chip come out right in front of the area I had just repaired. I am waiting for it to dry good and thinking about using epoxy again? The epoxy repair worked great I think.
 

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glass. gel coat or resin have no strength at all without the mat. i had something similar in my sanger mini cruiser. i'll post some pics if i get a chance. i ended up flipping it over for the repairs. also did the inside where the crack was to ensure it was perfect. been completely dry and crack free for 2 full seasons.

AP
 

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What you have is a bubble in the bond between the gelcoat and the initial layer of fiberglass, called the skin coat. Chines and strakes are tough to get the air out and so there needs to be a lot of skilled attention to these areas during the build.

Tap the strakes and chines with a screwdriver handle or dowel and the gelcoat will crack in the areas where there is a void. Grind it out with a small die grinder or small disc grinder and alot of focus. Wash the area down with acetone and let dry.

Tape off the areas adjacent to the crack and then with strips of cardboard or masonite that have been waxed, build a dam or wall against one of the hull's planes so the glass can be butted up to that point, filed and sanded. Then do the other angle the same way. Epoxy is overkill and the small areas you're talking about don't mandate it's use; polyester is fine.

In the smaller areas, instead of fiberglass materials (matt and cloth) use gorilla hair or resin mixed with matt strands and catalyzed. File and sand as above.

The key to this whole thing is to sand and finish along with the chines in long passes so you don't build whoops and curves.
 

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What you have is a bubble in the bond between the gelcoat and the initial layer of fiberglass, called the skin coat. Chines and strakes are tough to get the air out and so there needs to be a lot of skilled attention to these areas during the build.

Tap the strakes and chines with a screwdriver handle or dowel and the gelcoat will crack in the areas where there is a void. Grind it out with a small die grinder or small disc grinder and alot of focus. Wash the area down with acetone and let dry.

Tape off the areas adjacent to the crack and then with strips of cardboard or masonite that have been waxed, build a dam or wall against one of the hull's planes so the glass can be butted up to that point, filed and sanded. Then do the other angle the same way. Epoxy is overkill and the small areas you're talking about don't mandate it's use; polyester is fine.

In the smaller areas, instead of fiberglass materials (matt and cloth) use gorilla hair or resin mixed with matt strands and catalyzed. File and sand as above.

The key to this whole thing is to sand and finish along with the chines in long passes so you don't build whoops and curves.
Thats a great script right there. The only thing I could even add would be to keep the areas your patching very clean in between your coats. Adhesion issues can almost always be traced back to lack of prep and cleanliness, and sometimes rushing.
 

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Discussion Starter · #17 ·
Thanks guys for your help. I will be getting right on it. Other thing is I am new to these light lay up hulls and used to run heavy bass boats a lot and didnt worry about large boat wakes or waves that much. When this happened I hit a large wake and didnt see it in time and when I got off the throttle it was too late. I hit pretty hard when I landed. Is this a common occurence for jet boaters? I now see a lot of guys taking it easy in rough water and maybe I was to blame for this damage. I am new to jet boats but have been around a lot of boats and hot rods a long time. Just a thought.
 

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Hey Gunshot! Is there any cracking happening?...or is it just a gap of air between the lamination, air pockets (Glass to gel)? just for shitz and giggles what does that recessed area look like inside of the boat where some manufacturers install their subfloors, only reason why I ask, is because this has been a problem with smaller lighter boats that I have had dealings with!
if the area does not have a floor there or even if there is a floor that mates to the stringers...you may want to pull the floor to inspect if the lifting strake area is in fact cracking, all cracking repairs should be attacked from both sides of the area! a quarter round of wood would definitely help strengthen the bottom! I personally would do both if this is a problem!
Not trying to make a mountain out of a mole hill, just pointing out that there are other reasons why things do what they do!
Take pics!
 

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Sanger

AP67 and Hallett are correct. What you have in the pic. is air bubbles between the gel coat and the first layup. When you check out to repair again, use a wrench or small hammer, tap along the edge to find any more problems...Sand good before repairs.
I built the plug for your boat in 1974.
HARLAN ORRIN
 
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