I need some advice here. Suffren's stern has decided to bend it's keel down a little, so she doesn't sit flat anymore. I've tried to suspend her between two blocks and put weight in the middle, but that didn't work. I'm wondering if it's a good idea to make a cut in the sub-deck and remove some wood and bend the back end up and glue the sub-deck back together? Beaver
Now that I've been thinking for a while, I think Suffren's stern must have bent when I brought her in for the winter. Most likely it was the temp. change from outdoors to indoors. At least that's my guess. Beaver
I hppe that's not the case my ships are in the shed and it's below 0 degrees Celsius every night and now were at -7 below without wind chill.
Yeah some of that plywood sure does cause problems with temperature/climate changes. That's why I went with the more expensive plywood...less headaches later on. Some of my previously flat plywood now looks like I could build a hull just with the curl it has in it.
I was told once that for things like our decks and subdecks, that they should run with the exterior face grain of the plywood going the length of the ship, as that would cause less splintering along the edges and reduce the chance to warp as yours has when the wood expands. I am unsure as to whether or not this is the cause of your troubles, or how much of an issue it actually is. My Maru is cut opposite of that advice, and while I've had some edge spintering on the deck, my frame hasn't warped (though it was sealed up earlier than yours and is much shorter). Can you post some pictures? easier to offer advice on thigns we can see.
Your wish is my command..... Sorry for the poor image quality, very poor lighting. This is the whole boat sitting on a flat surface. She sits about 3/16" off the surface in this pic. The area pictured is where she sits the highest, but she sits high all the way down towards the bow. This photo shows how she sits when you lay the lower stern step-down on a flat surface. What I want to know is, is it bad enough that it needs to be fixed? I think it should be fixed, because when I look down her stern, it's uneven towards the very end. I guess the question really is, how should I fix it? Today I picked up a 5 by 5 sheet of 1/8" birch plywood from the local wood store. It's some really nice looking stuff. Looking forward to making decks after getting this problem resolved. Beaver
when you weighted it down in the middle, did it flex into shape or hold the bow? I'm skeptical that your proposed solution to cut a narrow kerf from the subdeck will work as I think you will have issues trying to rejoin the pieces.
If you do cut a kerf and do as you are thinking, a few thoughts: 1) Do it between two ribs, centered. 2) Once you've got enough kerf to compensate, weight it down to hold it flat 3) Use the thinnest fiberglass you can get, and wrap a few individual U-shaped pieces (bottom of U on outside) on it and apply epoxy. 4) Make sure the wood is fully butted up to each other, and then put a layer of wax paper around the joint. 5)take two pieces of scrap wood and two clamps, and clamp it with one piece of scrap wood on top and one on bottom. Keep it honest while the epoxy sets. I had an idea that's hard to describe, so I'll take a pic of some scraps cut how I want to say and post it Gimme a bit, I have to go shopping (7AM now my time)
@nick: When weighted down in the middle, it does flex down to where it should be. @Tugboat: Thanks for the suggestions. I'm looking forward to seeing the pictures of your idea. Beaver
I offer this with the proviso that I abhor butt joints with a passion, as they are artless and the weakest of all joints. With that said, I'm drawing a blank on another way to fix your hull, short of rebuilding it. So here we are. Should be strong enough for combat use. Just don't throw it Okay, here it is. The two pieces on the bottom are the two ends of the subdeck that you've cut to take out some length, now butted up against one another and ready for joining. We are looking 'up' from underneath the subdeck, k? The piece on top* with the holes is a 1/4" piece of plywood, epoxied to the bottom side of the subdeck to reinforce the butt joint. I would make it it the length of the window that it's in. You then drill two 1/8" diameter holes through the reinforcing piece and the subdeck, and drive a 1/8" dowel or brass pin through the holes, locking the reinforcing piece to the subdeck, and preventing lateral movement of the 2 sections of subdeck. Once the epoxy on this assembly has cured, I'd wrap a U-shaped piece of thin fiberglass around it (the bottom of the U facing out, the open 'top' of the U facing inboard. *Note the bevel on the long side of that reinforcing piece. That goes towards the outside of the hull so that you aren't having an illegally thick subdeck int hat section. Just to be safe, I attached this one 1/8" in from the edge, and had the bevel from 1/4" down to zero thickness on the outboard side.
Looks good, I think I'll try it. Now with the fiberglass U you were talking about, were you saying that the open part of the U be facing in towards the boat, or out? Thanks for the idea, looks very sound. Beaver
Tugboats rejoining suggestion is probably about as good as its going to get. You could probably get away with using some small wood screws rather than doweling it, but it is still going to be a weak spot - and you may need to do this in multiple locations along the length to remove the warp. You really dont want to pull out more than a single kerf width in each cut probably or you may find the gap is too big to be able to bring the sections together - remember youre trying to remove an expansion over the hull length by cutting in a few specific locations. Absolutely make sure you cut at the same location along the length of the hull on each side of the subdeck, or you might complicate your problem with the hull twisting. Last observation - youve got a few ribs that dont look quite vertical in those pictures, and at least one that looks a little twisted - you didnt force something did you? If those (and others) are under tension because they didnt fit the way they were supposed to be, they may be contibuting to your problem.
Today is the day that I hope I'll be able to fix Suffren's bent back. Might be harder than normal because my scroll saw is double parked I guess you could say. Beaver
Fix has been made. I didn't rap the fiberglass cloth around the break, yet. I'm going to wait until the epoxy cures and then do it. I did put a piece on top though just to help it stay together. Pics tomorrow....Maybe, Beaver
Not yet, the epoxy has just cured on the fix. When I cut the sub-deck and glued it back together, I did it in the shed. Not thinking, I left it out there to cure. Well the temp here hasn't gotten over 20 degrees for a while, so the epoxy just froze but never cured. I finally realized that the epoxy wasn't cured on Christmas morning, and brought her into the warm. So finally, she has thawed, and cured. Maybe today I'll get that U piece epoxied on today. After I get this fixed, you think I should secure the stuffing tube, so I can the secure my motor mount? Beaver
