Build progress and a request for help

[glen65]

I started to build a stitch and glue boat from plans I purchased and I've hit a problem that I could use your help on. First some background.

The build really went well and moved along fast until I tired to add the two front frames to the boat. The angles are impossible in my opinion. I spent a lot of time steaming and heating the front side of the boat only to have both sides crack when I tried to fit the frames in. I also tried wrapping the sides around the frame only to have them crack too. The plans call for 1/2 plywood.

I also had problems trying to bend the front bottom panels which also ended up cracking... again, after steaming and heating them. I got desperate and got some sheets of 1/2 PCV to try and form the bottom.

Attached are pictures of the "progress". So here's where I am. I had to rebuild the front with new sides and I've been able to stitch the upper part of the bow together. I'm going to go with a narrower front than the plans call for because of my inability to get the frames to fit without breaking more wood. The problem is that the bottom panels are for the original design. See this video for a better view of where it currently stands... https://youtu.be/W2AhCiaeKiA
At the end of the video, you can see the two frames that I'm having issues with hanging up.

What advice do you have for reshaping the bottom front to fit the new shape? Should I cut the bottom panels to remove some of the excess and try to reshape it?

[glen65]

IMG_20201010_095141973.jpgIMG_20201011_133947042.jpgIMG_20201010_164448416.jpgIMG_20201115_120141242.jpgIMG_20201115_120202560.jpg

[glen65]

IMG_20201121_113046172_HDR.jpgIMG_20201121_113040114_HDR.jpgIMG_20201126_132819534.jpgIMG_20201126_132834029.jpg

[David G]

OK... let' start at the beginning: what plans/boat?

Hard to diagnose long distance, but let's see what we can do.

You said 1/2" plywood was called for. Did the building instructions or plans specify a specific type, grade, and/or species of plywood?

I ask because that rotary-cut softwood plywood you show doesn't seem to be up to the task. And I'm not surprised... as it appears to be a very low-end product (CDX maybe?).

One guiding principle of building small boats from plans. Assuming you've found some proven plans from a reputable designer... then Build To The Plan. If it doesn't seem to be working... figure out why. Ask the designer. Ask on a forum. Ask a local boatbuilding group. Hire a local boatbuilder for a brief consult. As soon as you start 'winging it' without knowing where the problem lies... it's unlikely to turn out well.

[wizbang 13]

good god bin that junky ply.
build a scale model.

[wizbang 13]

bin those frames too
there should be no steaming involved on an epoxy boat

[glen65]

Thanks for the response. It is a Spira San Diegan. The bill of materials on the plans says 1/2 inch hardwood ply.
Screenshot 2020-11-26 at 6.09.19 PM.png
However, when you get to the section on the bottom, it says to use Fir ply.
Screenshot 2020-11-26 at 6.09.41 PM.png I did contact him and said... "As your plans call for on the San Diegan, I used 1/2 inch softwood ply for the bottom panels. However, I'm unable to get the sharp curve of the front end to come together. Do you have any suggestions? I am thinking of a series of scoring the outside of the ply with a circular saw to bend it. Looking forward to your thoughts," His response back to me was "Yes, cutting reliefs is just fine. You can also use hot water to steam it but most of the better 5 ply ply is quite stiff. The first one I built with 3-ply Meranyi that was floppy enough to make the curve with a little boiling water poured on it. I'd also consider using a Spanish Windlass through two hole to force it together until you get the inside bonded."

[wizbang 13]

That a designer would say yes to scoring the ply or steaming it is shocking to me.
but that cdx you are using has voids in the center,super clapped with knots...it is just awful.

[Dusty Yevsky]

Torturing 1/2" CDX into that extreme bend just isn't going work. If you can swing it financially get some thin aviation grade plywood and build up the section to the desired thickness. I'd also think about strip building that little section.

[Stormp]

I'm not sure what you have at your disposal but if it's just the forward section giving you trouble, you could buy a single sheet of 1/4" ply and cut the forward section off completely, router a step into the 1/2" stuff, and then build back the missing section with overlapping strips of 1/4" stuff. The strips will take a bend much more easily, and if you epoxy everything it'll be solid as a rock afterwards. The Point Comfort skiffs take a similar approach, I think.

[glen65]

I don't want to bash the guy because he has a lot of very popular and proven ply over frame plans but I've lost all confidence in him on this stitch and glue plan. Not just based on the advice he has given me but also because I found some wrong measurements in the plans too. That's why I'm on here asking all of you.

Thank you for the helpful responses.

[wizbang 13]

Glen,
Some better ply, and a good scale model, will make yer next boat easier,better and safer.
Good plywood CAN be bent and SHOULD be bent. Curves make it stronger.
I dunno about Spira paticularly, but the plan sez 20 gallons of epoxy...now, I use a lotta epoxy,more than most here I'd guess, but 20 gallons in a skiff like that?
That is absolutely NUTS !!!
I do not believe Jeff Spira has ever shown up here on the WBF.

I've built at least 20 SnG boats, none to a plan ,but my own cardboard (matt board actually) models. Take a look at how far good ply can be bent.

http://forum.woodenboat.com/showthre...ild&highlight=
bruce

[Arlc]

Then there is the “Well, that didn’t work” course of action. You aren’t that far down the build path. I’d learn from the experience and find better plans.

[glen65]

Thanks. What are your thoughts on the number of gallons of epoxy?

Glen,
Some better ply, and a good scale model, will make yer next boat easier,better and safer.
Good plywood CAN be bent and SHOULD be bent. Curves make it stronger.
I dunno about Spira paticularly, but the plan sez 20 gallons of epoxy...now, I use a lotta epoxy,more than most here I'd guess, but 20 gallons in a skiff like that?
That is absolutely nuts. I do not believe Jeff Spira has ever shown up here on the WBF.

I've built at least 20 SnG boats, none to a plan ,but my own cardboard (matt board actually) models. Take a look at how far good ply can be bent.

http://forum.woodenboat.com/showthre...ild&highlight=
bruce

[glen65]

Then there is the “Well, that didn’t work” course of action. You aren’t that far down the build path. I’d learn from the experience and find better plans.

I don't have the money to start over with new wood again.

[wizbang 13]

Had you budgeted the Spira boat for TWENTY GALLONS of epoxy?
Cuz you could save enough on 15 gallons of epoxy to buy some Hydro Tek instead.
A better plywood will not need sheathing in fiberglass. just paint..
ply.

[Arlc]

Some people just like banging their head against the wall. Have at it. Glen65, ever heard of the concept called sunk cost? Throwing good money after bad? Cutting your losses?

[Rich Jones]

My two cents worth of advice. Buy 3/8"marine ply for the sides instead of 1/2". Still, that is one tortured twist up in the bow.
I'd go with a Sam Devlin design. He is well known with proven designs.
Sorry this is not turning out well for you, but don't give up!

[David G]

Yes, you're going to have to toss that low-end plywood. There's simply no way to make it workable that I can think of. Yes, that's probably more epoxy than you'll need. And yes, you can dial way back on the quantity of epoxy. Spira boats are built stout. I'm about half thru one, so I know. You won't need to sheath the outside in fiberglass, esp. if you switch to a meranti ply.

Also... two thoughts on your tight bend forward. First - look into using 2 layers of 6mm (1/4") plywood in those locations. Elsewhere is fine also if you're careful to make sure there are no voids between layers. But 6mm bends WAY easier than 12mm. Second - when there's a tight bend forward, it usually works far better to attach the plywood to the stem firmly, let the glue dry, than work your way toward the stern.

Good luck!

[johngsandusky]

I haven't seen the plans, but that bend looks unlikely to work.
I would try bending battens around the frame lengthwise to find where the side panels would naturally meet at the stem. Cut the battens from the same ply your using for planking. This might extend the length a bit, but the sides will come together without breaking.

[epoxyboy]

Thanks. What are your thoughts on the number of gallons of epoxy?

I built one ofJohn Welsford's 17ft lapstrake designs (Pathfinder)I don't think I used 20 litres - five gallons to you. Not S&G, but it had a load more glued joints.
I can't see any sort of 1/2" / 12mm ply having a hope in hell of ever doing what it needs to there, assuming you have that forward frame located correctly, and it's the right shape.
Pathfinder has a very aggressive twist in the equivalent plank, but it's only 9mm ply, the forward frame is relatively further back, and its a narrower angle V. In other words, thinner plywood, lots of twist but over a longer distance, and it has far less bend around the forward frame to the stem.
Using quality marine ply, it was doable, but I suspect really pushing the boundaries. Some builders kerfed the ply in that area and a few others strip planked it - which I think would be the best option here. But seriously, is that frame in the right place/the right shape? Are the panels the right shape? Material thickness and quality aside, something just doesn't look right.

Pete

[glen65]

Hello,
Thanks all to the ones with the helpful comments and suggestions. I'm positive that I measured the frames and the placement correctly. I've triple checked them and even had my friend verify the measurements. I just think the designer never built one of them. I've decided to add a kealson and stem and ship plank it. I specifically chose this design based on all of the positive feedback and the ability to use typical lumberyard materials. At this point, I don't have the money to toss it as other's have suggested. I'm sure I can make it work.

[alkorn]

I looked at the photos of your San Diegan on the Spira website, and it seems like the ply has some kind of weird bend near the stem.
slide_sand01.jpg

[Slacko]

Those photo's in post #23 look very suspect for some creative construction.
I would take the advice to make that bow section from 2 layers of 9mm laminated together rather than 18. 3 layers of 6mm are even more likely to give a fair curve.
I would butt block the first layer to the 18mm where you cut it, then scarf the additional layer or layers onto the hull once the first layer is glued and dry. Epoxy is your friend for less than perfect scarfing.
It will be 1 additional sheet of much cheaper material and you are sure to use the leftover for interior work.
Expensive ply is going to give a more reliable shape due to the likelihood of the stuff you are using having voids and those knots.
Meranti will last longer too, but sitting on a trailer under cover will mitigate mst of those worries.
Get back into it!

[glen65]

Trust me, I have the plans for that boat and the way the plans go, the end product should not look like the front of that boat in the pictures. My guess is that the person who build it had the same problems as me and had to get creative to finish it off.

[Arlc]

Common boat building equation for budgeting the cost of a build:
1/3 hull
1/3 interiobr /> 1/3 finishing
1/3 upfitting.

Oops, that’s 4/3rds.
Well.... that’s the way boat building goes.

Glen, if you don’t have the $$ to throw away a partially completed hull and start over with good quality material and/or plans you likely don’t have the $$ to complete the build.

[Arlc]

Common boat building equation for budgeting the cost of a build:
1/3 hull
1/3 interiobr /> 1/3 finishing
1/3 upfitting.

Oops, that’s 4/3rds.
Well.... that’s the way boat building goes.

Glen, if you don’t have the $$ to throw away a partially completed hull and start over with good quality material and/or plans you likely don’t have the $$ to complete the build.

[wizbang 13]

Trust me, I have the plans for that boat and the way the plans go, the end product should not look like the front of that boat in the pictures. My guess is that the person who build it had the same problems as me and had to get creative to finish it off.

This is why I recommend a good scale model...even for the simplest 8 foot pram. The mistakes cost five bux. Both the designers mistakes and the builders.

[DoctorB]

I was just playing with some paper cutouts, by eye from your photos. Do you think there is any chance that right and left sides are flipped?

[Slacko]

There we go, if you put it out there the solution will be spotted.

[epoxyboy]

IMG_20201115_120141242.jpg

This makes it look like the bottom panels are around a foot short, but it's hard to tell if it's just a camera angle thing. The bottom edge of the top panels has to be the same length as the top edge of the bottom panels, or there is no way this can work.

Pete

[amish rob]

I was just playing with some paper cutouts, by eye from your photos. Do you think there is any chance that right and left sides are flipped?

Oh, boy, have I flipped panels before...

[willin woodworks]

i was just playing with some paper cutouts, by eye from your photos. Do you think there is any chance that right and left sides are flipped?

bingo!!

[timo4352]

Sorry to see this is not working out for you...
But, I don't think picking this boat was a good choice from the beginning...
Sorry to say so, but there is only one picture of a completed one, and it looks rather crudely built at that... not too confidence inspiring...
If this is the type of boat you want to build I suggest you look at the Lumberyard Skiff.. it is a proven design and many have been built.
You may be able to re-use what materials you have already purchased to build it. Better ply strongly suggested, but it's your boat / your call.
You won't need 20 gallons of epoxy or 90 yards of fiberglass cloth either.
Good Luck.