TDB Classic cracked keel! What to do?(PICTURE ADDED)
- Thread starter Gary F
- Start date
Lou Tisch
Well-known member
Gary,
Echoing some of what Tom A. said.
Grind with 24-36 grit both inside & out. Grind a bigger area than you think you need. I'd go about 6" all around inside and probably 3-4" all around on the outside. As Jay said, you can use thin C/A (alpha cyanoacrylate adhesive-also at a model airplane hobby shop) to toughen it up but that will be accomplished with the laminating.
If using polyester resin (that's what I recommend), you MUST laydown a layer of CSM (chopped strand Mat) FIRST. This is required to give a bulk to your material to give a bond. FYI note: epoxy is fine with glass alone but Polyester MUST have a bonding layer of CSM.
Start with a piece to cover the entire area. Catalyze your resin (do not EVER apply uncatalyzed to anything), wetting it out. Once wetted, lay it in place. Successive layers may be smaller until the area is filled. You can follow the CSM with 1708 (that's 17-18 oz. sewn cloth-usually at 45-45 with a layer of 3/4 oz. CSM on the back). Prewet the CSM side and place CSM side toward the area to be repaired. Roll everything down with a resin roller and eliminate ALL airbubbles.
On the outside, do the same and overfill. You can then grind it down, smooth it out and gel coat it afterwards.
Holler if there are any unanswered questions.
Lou
Echoing some of what Tom A. said.
Grind with 24-36 grit both inside & out. Grind a bigger area than you think you need. I'd go about 6" all around inside and probably 3-4" all around on the outside. As Jay said, you can use thin C/A (alpha cyanoacrylate adhesive-also at a model airplane hobby shop) to toughen it up but that will be accomplished with the laminating.
If using polyester resin (that's what I recommend), you MUST laydown a layer of CSM (chopped strand Mat) FIRST. This is required to give a bulk to your material to give a bond. FYI note: epoxy is fine with glass alone but Polyester MUST have a bonding layer of CSM.
Start with a piece to cover the entire area. Catalyze your resin (do not EVER apply uncatalyzed to anything), wetting it out. Once wetted, lay it in place. Successive layers may be smaller until the area is filled. You can follow the CSM with 1708 (that's 17-18 oz. sewn cloth-usually at 45-45 with a layer of 3/4 oz. CSM on the back). Prewet the CSM side and place CSM side toward the area to be repaired. Roll everything down with a resin roller and eliminate ALL airbubbles.
On the outside, do the same and overfill. You can then grind it down, smooth it out and gel coat it afterwards.
Holler if there are any unanswered questions.
Lou
Last edited:
Bob B
Well-known member
Gary,
I dont know if the TBD was gelcoated or painted, but I would consider using laminating resin which will require PVA to fully cure but will allow you to work the repair area without the wax in regular resin rising to the surface each time you stop working.
I would not recommend epoxy as the original hull is polyester most likely (I dont think they used vinylester resin) and should be matched with the repair. As stated an inside and outside layup will be the best way to go and in this case can be reached. A small right angle air grinder will be very useful in the tight space inside with a 3M rotolock sanding disk for grinding the inside. outside a 4 inch electric grinder is best. DA sanders are not up to glass work except for the finish fairing.
Last layer on inside and out should also be CSM for sanding material to fair in the repair without cutting into the structural cloth layup schedule under it.
Good respirator is required with glass work for dust and fumes. Also a full tyvek suit and painters hood will help with the itch from the dust.
Search on line for a Fiberglass repair tutorial as the layup is not hard but may seem daunting without some pictures to explain it.
I dont know if the TBD was gelcoated or painted, but I would consider using laminating resin which will require PVA to fully cure but will allow you to work the repair area without the wax in regular resin rising to the surface each time you stop working.
I would not recommend epoxy as the original hull is polyester most likely (I dont think they used vinylester resin) and should be matched with the repair. As stated an inside and outside layup will be the best way to go and in this case can be reached. A small right angle air grinder will be very useful in the tight space inside with a 3M rotolock sanding disk for grinding the inside. outside a 4 inch electric grinder is best. DA sanders are not up to glass work except for the finish fairing.
Last layer on inside and out should also be CSM for sanding material to fair in the repair without cutting into the structural cloth layup schedule under it.
Good respirator is required with glass work for dust and fumes. Also a full tyvek suit and painters hood will help with the itch from the dust.
Search on line for a Fiberglass repair tutorial as the layup is not hard but may seem daunting without some pictures to explain it.
Bob B
Well-known member
Here is one link http://www.boatus.com/boattech/casey/17.htm