Clamping down the deck to frames

[Captain Al]

Is there a type of clamp that can be used to hold the ply deck down on the tops of the frames while glue dries? I can't figure out a way to do this. It would have to be sort of a T clamp. I have a deck to glue down on Bounty that has a good deal of sheer to it and a couple of the aft most points of contact with the frames require a bit of push to get them to sit down. I am using weights on six other points but these particular frames would require more weight than I want to place on the model itself. I was considering putting small shims on the tops of the frames so the deck doesn't need to curve down as much, but this would not only change the sheer of the deck but would require some additional wood on top of the cross beam. And of course, a pin down into the frame could do the job as well. But my first priority would be to clamp down. Any suggestions?

[Captain Al]

Here is a picture of the two offending deck to frame positions.

[Mike Y]

That looks like a weights from the knitting machine!

Instead of clamping, it's better to bevel frames, to have a proper contact between deck and the frame.

Also, the frame in the middle of your photo is significantly lower then the one on right side of the photo, if you clamp it down, deck would be bent. Is it desired? Or maybe it's just an effect on a photo?

[Captain Al]

You got the knitting machine weights right, Mike. Relics of my wife's avocation. The deck does rise significantly from mid ship to the stern, so the frame on the left should be lower. I think also the photo exaggerates the height difference somewhat. There is a modest bevel to the tops of all the frames. In fact, its a tricky compound bevel -- it bevels down from the inside to the outside of the frame to accommodate the slope of the deck mid point to side, and each one bevels a bit upwards toward the bow or stern. The picture doesn't clearly show that either. If I were to put any more bevel into either of these frames, the deck would be even further from making contact. This morning, after closer inspection, I think I am going to shim those frames like I have others, just making sure I shim them so the deck sits on them slightly higher to the stern. Then the clamping won't need to be so radical and still the sheer will be fine. It may not look like it in the photo, but in person its laying nicely except for the gaps.

[shihawk]

maybe it wouldn,t suit your case but have you considered nailing or pining it down .just a thought

[jud]

Does your plans show such an arch? My guess, is no.

jud

[Captain Al]

Good question Jud.  I am a novice at reading plans, and the only drawing in my array of plans that would seem to answer this is the one that I took the heigts of the frames from.  If, in the end, after all the adjustments and shims etc. that I have been doing in order to get the sheer right, the frames actually are lower at their tops than they should be, then the arch of the precut false deck would have to be greater.  But for the most part the arch conforms nicely to the arch of the beams.  The edge of the deck, however, extends a bit over the frames, again indicating that the arch is OK but the frames are low.  I'm going to have to deal with that as part of the process of fairing the frames for planking.  Like much of this adventure, I am going on the theory that if there's a way to make it work, I will find it.  Whatever may have been the source of these problems, I've surely learned some valuable lessons.  POF is definitely more challenging than POB.

[NMBROOK]

Looking at the picture the second frame from the stern(the one with the weight on top to the right in pic)needs trimming down.On Bounty the sheer is a smooth arc with the dip amidships.Your deck is dipping,but is wanting to bend the other way when it reaches the offending frame.Trimming down by 1 to 2mm(a guess looking at the pic) will make a massive difference.Best way to tell is to take the deck off and get a piece of square timber say 5x5mm and sit it on the top of the frames.Push the middle down so that it touches the frames and you will see if this frame top is the odd one out.There should be a smooth arc from bow to transom with no high or low spots.

 

Kind Regards

 

Nigel

[Captain Al]

Gotcha.  I think I have it now (took all day of shimming and trimming) where the low point is at frame ten and the deck lies in  a smooth arc up to the bow and transom.  All the beams are making good contact with the underside of the deck, and there is a nice, smooth arch from the midline to the deck edges  (is that called the gunwales; pronounced gunnels?).  I've discovered a couple cosmetic details I want to do on the middle deck, so I will probably not glue down the main for another day.  Thanks all for your pointers.  For better or worse I can't wait to get this deck laid.  Please, no comments on that last sentence.