Fiberglass Hull Repair on Strake

[slader99]

Boat is a 17' Hourston Glasscraft.

My roller trailer came apart on a rough road and one of the roller mounts ended up digging into a strake. By the time I was home and saw the issue it had worked it's way well into the hull.

I've removed all the damaged material. The section measures about 4" long, 1" wide and is approx 3/8" deep at most (measured from corner of strake). The damage extended all the way to the stringer which seems to be nice solid wood. Between the tapered profile of the fiberglass strake and the stringer there was a gap about 1/16" to 1/8" thick with a hard rubber substance; I figured maybe some sort of polyurethane or adhesive that is used when bedding the stringers? I picked out the section where the repair will be with an exacto blade. The pictures might make it look like there is some bowing around the damaged section but the surrounding area appears true when measured across with a straight edge.

I have some marine-tex epoxy that I've used for other much smaller repairs. It seems to have worked pretty well. My original plan was to use this marine-tex product in this application but I'm having second thoughts.

If it was your boat and you were planning on keeping it would you be hesitant to use the marine tex? Do I need to feather this area out further and repair with fiberglass?

Thanks in advance or any suggestions.

Cheers

 

[mickyryan]

i would do it with glass

 

[Scott Danforth]

I would feather out further no mater what material you are planning on repairing with. the ratio of distance to feather to depth is about 8:1. so if you go 1/8" deep, you feather out 1"

 

[Woodonglass]

Yup, I totally agree feather it out and use 2-3 patch pieces cut in football shapes eash 1" larger than the preceding. Put the smallest down first. Use some fairing material to finish it up and it'll be good as new. 2-3 hour job.

 

[slader99]

Thanks for the advice. Feathered out further as suggested. Original boat was built with poly; any suggestions for type of mat, resin and filler for applying upside down? Should I be filling the gap with chopped up fiber/resin paste first? Any tutorials or posts describing the process you can recommend?

Thank you,

 

[mickyryan]

you can use plastic on a table wide enough for repair then build the patch on the plastic then get under hold it up until it starts sticking then make sure there isn't any air just a guess on my part since i havent done it but that's how i would if i had to since they are small

 

[Woodonglass]

If you make the patch with 3-4 layes of 1708 and Poly resin and put the small football shaped patch on the Wood spot and then apply each progressively larger patch on after that, it should fill in nicely. Put the last Patch piece with the CSM hairyside facing out. This will make for easier fairing and almost no pattern bleed thru. If the middle of the patch is a bit low just using some 3M Premium filler to level it out.

This video is KINDA like what you'll be doing.
https://www.bing.com/videos/search?...73ABBCF8F8781EBBFE6873ABBCF8F878&&FORM=VRDGAR

I've done patches on the bench using plastic laying the largest piece first and smallest last then coating with resin and carrying it to the boat. Use a 4" paint roller to roll it in place and remove air pockets. Leave the plastic on for a few hours and it will cure the resin to a non sticky cure and peels right off.

 

[slader99]

I ended up going with poly resin instead of epoxy. I couldn't make multiple layers of biaxial conform to the sharp curves of the strake upside down; they wouldn't stay in place. I ended up starting with a piece of biaxial then using alternating layers of cloth and CSM to build it up. I used 5 or 6 alternating layers all together in 2 stages over 2 days. I cured it at the end of each build up with some PVA that I brushed on then washed off with soap the next day. Sanded and faired with 3m premium filler then applied a thick layer of gel coat. After sanding the gel coat flush with the surrounding area it looked great! And now it's hidden under a coat of bottom paint

I'll be able to boat worry free knowing the repair is solid. Probably will take it to someone else next time though, sanding bottom paint and fiberglass upside down sucks ;(

Next issue is the cap covering my cap/transom seam along the top edge of my stepped transom. But that will be an issue for another post.

Thanks for the suggestions everyone.

Slader 99