WarBird's Grid Repair

Now that owners in the east have their boats out and need something to do besides go skiing, I thought this might be of help to anyone who values these great little boats and would like to keep sailing/enjoying them at their original potential.

WarBird is my second L28. My first, Voila, had similar issues but as she was only 13 years old when we bought her and WarBird was 28 when we picked her up in Milwaukee this summer, her grid de-lamination was further advanced. WarBird was otherwise the most original L28 of the four boats on the market at the time, justifying a 4,000 km round trip to pick her up.

All boats suffer damage when hitting a submerged immovable object as the keel pushes back and up at the top rear as the boat tries to pivot over the object. You do not have to hit anything to separate this grid structure from the hull. When I had Voila and was experimenting with tight rig tension, the starboard side grid at the base of the shroud tension rod separated with a loud 'pop' before the start of a breezy race. The pit crew calmly turned to me and asked if that is something we should be concerned about. I returned an equally calm reply of 'no', but immediately after the race went below to discover a separated grid from the hull. I assumed correctly that I had passed the tolerable limit of rig tension :-(

Voila also had a cracked grid under the battery box, which the surveyor missed and could not be seen until the battery and support platform where removed. WarBird's was more noticeable as the crack was at the head entrance/threshold box just under the floorboard level. As fiberglas is flexible to a point, separated tab sections are not as obvious and will not look 'separated' necessarily as they will settle back to normal after the hull flexes during impact. Tapping with a small hammer along ALL the tab sections on the box grid will soon tell you if the bond is intact (solid sound) or not (not solid sound). Do not be fooled by what looks like 'filler' material under these tabs, especially if it is not original (i.e. not painted over grey) and/or you see a small crack line running under the tab. Tapping and probing aggressively with a chisel and hammer at any crack will soon tell you if this tab is bonded or not. If the bond is intact, you won't be able to remove the filler. If it chips away in bits… you've got the beginnings of this job.

As with any repair/upgrade, proper preparation is the key and the boat needs to be on her trailer/cradle & all rig tension slack, or mast off, before commencing this repair/upgrade. Any area needing epoxy/cloth MUST be stripped of gelcoat (the messy part) and suitably roughened so the new epoxy will have maximum bond. In places where I left the tabs in place, I drilled them to add to the 'grab' the epoxy would have. See photos. If I was doing this job again, I would just cut off all the tabs that needed bonding.







This is not a rocket science repair job, but requires determination to aggressively dig out or cut off the separated tab and build it back up with epoxy and cloth. A Dremel multi-max oscillating saw/grinder is invaluable for cutting the tabs and grinding out the old filler in tight places. For rapid removal in exposed areas, a high speed orbital grinder is faster, but a lot messier. Once cleaned and roughened enough, vacuum and wipe down with acetone before laying epoxy. I used West System Epoxy with Cab-O-Sil filler in places where tabs were left (see photos) to build a smooth transition to the final application of two to three layers of Knytex cloth wetted out with epoxy. Knytex is a combination of chopped strand and directional weave that conforms to a variety of shapes more easily than just directional weave will. With epoxy resin you can overlay multiple layers while the first layer is setting up. The benefits of this is a faster completion time and a stronger bond. Using a slow hardener and working in small batches keeps the job manageable.










Rather than replace the wood floor supports on the hull in the aft area between the head and galley, I made new supports and epoxy/glassed them to the underside of the floor boards in that area. A previous WarBird owner had cut that floorboard in two pieces so one piece remains under the stairs while you lift the other to clean/mop up the bilge area under. A good idea.

After all was done and good, a coat of paint will finish the job. Painting epoxy requires special preparation but is well worth the extra effort and makes cleaning a lot easier…. OK, OK…. so not everyone is interested in a clean bilge and as there are no UV rays down there, the paint thing is for the truly fussy, i.e. me :)



Many thanks to 'ffletch' (Voila) for expert advice on this project. I learned a few things and the job was very satisfying, knowing I have given this great little boat a new lease on life. I contemplated re-naming her Phoenix, but she hasn't really risen from the ashes, so WarBird she stays. We're looking forward now to getting her wet again and go play with Voila.

cheers,
George

Edited by George S. - 19 November 2013 at 8:54pm

yes you are supposed to copy and paste but you have choices.... look closely at the links they supply. Sometimes there are 2 choices for forum links

"Because as it is now you are taping over delaminated flanges. There is no way to get a good bond under the flanges without removing them"

hi Bill, I got at least a better bond than original. All material was removed and the flange underside and hull under were meticulously cleaned and roughed up before mixing a paste of Cab-0-Sil and epoxy and forcing under the tabs and through the holes drilled. While still wet the next layers of epoxy/cloth were added creating a direct bond to the hull when set. Agreed that the better method is to cut off and the second phase of project, the aft section incorporates that.

Edited by George S. - 19 November 2013 at 8:58pm