75 Crestliner stringer replacement project

[kevdog2000]

I have to replace the rotted stringers and floor on a '75 Crestliner Apollo and need a little advice. After removing the stringers, I still have the fiberglass mat that was used for tabbing attached to the hull. Do I need to completely remove the old fiberglass tabbing or can I grind it down a little and re-glass over it? Also, there appears to be dark areas on the bottom that look like mold(?) Do these areas need to be ground down to ensure good adherence for the new fiberglass?

This my first time attempting this type of project. Thanks for any help!

 

[wooky30014]

While no expert here kev, I too am in a similar project. Yesterday I finished removing some of the tabbing that held my old rotten stringers, see my thread "And Away We Go" to see the pics. The remaining tabs I'll be sanding the edges down smooth so no humps and bumps for new stringer tabs. From what I was told and understand we'll need to roughen up the surface a little so resin will have something to bite into and a smooth surface to cut down on the possibility of air bubbles under the new glass

 

[Woodonglass]

I'd HIGHLY recommend using a sawzall with a flexible blade and cut the stringer channels completely out. You'll never be able to get the needed bond if you don't. The Old Glass needs to be ground down to nice PINK fresh glass and then cleaned with acetone prior to laying any new glass. Check the 2nd link in my signature line below for some helpful info.

 

[kcassells]

And post some pics asap. Take alot of pics and measures for when you go to put it back together.
PS...Welcome aboard!

 

[kevdog2000]

Thanks for the info! I hadn't thought about the air bubbles being trapped by the old fiberglass. The old glass is pretty heavy woven material and there would be a lot of small air pockets left. Grinding and dust here I come! In regard to Woodonglass, I've gotten down to the pink in some areas but if I get the woven smoothed out will that be enough or do you recommend complete removal down the hull? I'll try to get some pics up...trying to figure that out.

Another question, after reading many forums, when installing the new stringers, I plan to put small pieces of foam down first and then bond with PL. (Will use peanut butter and full enclosure of fiberglass after that) After a little shopping, I found out there are different grades of PL, 200,500, 1000. Will the grade matter? I have some 500 right now but haven't started the bedding process yet..

 

[Woodonglass]

I think you'd find reading this would be helpful...Fabricating Decks, Stringers, and Transoms

 

[kevdog2000]

I read through your post and found the diagrams very helpful! Thank you! Here's a couple pics