Re-coring project underway
- Thread starter Sefuller
- Start date
Dumb question. How did you remove marine grade plywood core so that you can seal the core with epoxy plugs? A bent nail aint' gonna get it, you have to provide compression plugs (plywood is not enough), and you need to keep the water out.
Also, although G10 is really cool, there are structural grade pre-cast FRP products that are still stronger than the rest of your boat and are much less expensive. The ONLY reason to use G10 is for super high loads and threading. The rest of the time it is pure overkill.
Also, although G10 is really cool, there are structural grade pre-cast FRP products that are still stronger than the rest of your boat and are much less expensive. The ONLY reason to use G10 is for super high loads and threading. The rest of the time it is pure overkill.
I'm going to guess that he pre-drilled oversized holes in the plywood, in the same location that the original holes were..........
Yes - I marked and pre-drilled all of the deck penetrations in the plywood and balsa core and filled with thickened epoxy prior to laying the glass. @thinwater if you look at post #15 in this thread you can see the holes in the plywood prior to filling. I think the following post shows them after being filled.
Last edited:
The bottom skin on my boat is quite thin, however in the areas where the deck fills are on my boat, the liner and bottom skin appear as one. In other areas there is a distinct gap between the liner and bottom skin. The top skin is approximately 1/8th inch of glass (not including gel coat).
Got the core glued in the starboard side yesterday with help from some great friends - one person mixes batches of thinned, neat and thickened epoxy non-stop while two of us wet out and place the pieces of core. This project has been blessed with exceptionally mild weather, however for this part of the project we had the coldest temps so far - 16 degrees when I got to the boat at 7:00 Saturday morning. I turned on the halogen work lights and fired up the propane heaters and by the time we started gluing around 10:00 the deck surface was up to 45 degrees - pretty close to the threshold for West Systems epoxy. In order to insure a full cure I spent the night on the boat in order to keep the heat going nonstop . The starboard side went a little faster than the port side - about 4 hours for gluing and installing the core. The prep is the time consuming part, probably 16 - 20 hours to remove the old core and clean out the perimeter margins, and about 4 hours to cut and fit the new core. Some time in the next week or two I will grind the bevels around the perimeter, sand down the areas of thickened epoxy that squeezed up between my sand bags and then it will be ready to laminate.
One interesting discovery I made quite by accident while prepping the starboard side is that the mounting hole spacing on my genoa tracks is not identical from one side of the boat to the other! Since I am overdrilling and pre-potting the holes this was an important discovery! Thankful to have thwarted Murphy this one time.
One interesting discovery I made quite by accident while prepping the starboard side is that the mounting hole spacing on my genoa tracks is not identical from one side of the boat to the other! Since I am overdrilling and pre-potting the holes this was an important discovery! Thankful to have thwarted Murphy this one time.
Last edited:
^^ OK, so how do you remove the plywood core? Or are you going to drill and fill before placing the top skin (you could easily see the plugs through)? You really do need the top skin keyed in, as other wise it tends to work loose under load (I've done the lab testing), leaking and also not bearing any load.
@thinwater - Not sure I understand your questions exactly? I won't be removing any plywood core - I predrilled all of the holes where the fasteners will go oversize ahead of time and they are filled with thickened epoxy - you can see the filled holes in the plywood that are for the genoa track. I also overdrilled the chain plate holes and the deck fill holes to provide an epoxy barrier.
When you say "keyed in" what do you mean? I will be grinding a 1 1/2" wide bevel in the existing non-skid margin I left, and laminating in three layers of 1708 - each layer 1/2" larger than the previous as they fill the ground out bevels. Posts #18 and 19 in this thread show the bevels on the port side before and after laminating.
When you say "keyed in" what do you mean? I will be grinding a 1 1/2" wide bevel in the existing non-skid margin I left, and laminating in three layers of 1708 - each layer 1/2" larger than the previous as they fill the ground out bevels. Posts #18 and 19 in this thread show the bevels on the port side before and after laminating.
Looks fantastic, and many thanks from all of us for sharing your skills and experience. Quick question...what about the non-skid pattern on the deck in the areas that you have re-cored? Will you be able to replicate the existing pattern?
@GregL564 I will be rolling KiwiGrip over all the non-skid areas - trying to match the pattern with a mold and new gel coat is way above my pay grade. I used KiwiGrip on my cabin top after doing repairs there and have been happy with it so far. It's a little harder to clean, and it takes some planning and effort to get it to look consistent but overall it's pretty easy to work with. I did find that you can't skip the prep work of either sanding the existing non-skid pattern completely away or filling it in with fairing compound or else it will telegraph through the new KiwiGrip.
I thought you indicated in post 29 that the holes did not line up, and that you discovered this after the laminate was in. I did not read carefully. My bad.
By keyed-in I meant the the plug must be larger than the hole in the laminate above or below. That is why we remove core with a bent nail or similar. I've known people to simply drill a large topside hole, not realizing that is not the same thing. Since you will be laying the laminate on top of the potting and drill correct size holes, that is excellent. This comment was not for you, but for other readers.
My question is purely hypothetical, it seems. How would you remove ply core normally? I doubt a nail would do it, so some matter of Dremel cutter, I presume.
Always glad to share tips and techniques with a fellow restorer. My fiasco: http://forums.sailboatowners.com/index.php?threads/and-so-it-begins.123244/ I did go goofy and remolded the original nonskid in gelcoat. Fun and frustrating at the same time. 3 years in and I haven't been bashful about testing the limits and all is good. Even the T Nuts inbeded for the stantions have endured yanking, people hanging from lifelines and pulling over to the dock.
