Movement From Forms Prior To Fiberglassing

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RustBelt
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Joined: Tue May 15, 2018 11:24 pm
Location: Iowa

Movement From Forms Prior To Fiberglassing

Post by RustBelt » Wed May 16, 2018 7:09 pm

Hi Fellow Builders,

As with most new members, I’m starting my formal introduction to the board with a possible problem. Hopefully by speaking up, I can get over the issue and get to the finish line. You have all helped so much getting my build to where it is today, I knew exactly where I should go to get some advice.

For background, I’m building a Ranger, stapleless construction, and I have the hull complete (whiskey plank in, outside stems on, still fairing though, waiting for fiberglass). Looks fantastic. While taking a breath to celebrate getting this far, I had a series of life events that took me away from the process for a couple months (moving houses primarily). Getting back into it this week, I notice that the hull has sprung off the forms a bit (1/4”-3/8”) at the bottom flat of the canoe (Stations 0-4, bow and stern). Makes sense that the wood would move, as we transition from winter to spring with humidity returning. Eyeing and sighting down the hull, I couldn’t see the movement in any sort of obvious deformation, incongruity, or buckling. I only discovered it pressing down a bit while fairing.

I just wanted to check in to see if this is going to be ok, or if my delay put a permanent issue in the hull going forward. The strips were obviously tight to the forms for glue-up and setting at the time they were applied, but now the bottom doesn’t perfectly match the mold forms. Perhaps I’m over thinking it and being too particular, as I’ve seen canoes being built stapleless outside in high humidity and in rougher conditions than I could imagine (I’m building in the basement), but I haven’t found much information on the amount of movement expected off the forms when removing clamps/staples prior to fairing and fiberglassing.

Should I be thinking about getting the hull back down to the forms with some hot wood glue until fairing and epoxy is done? Will fiberglass and epoxy one one side really even correct the issue or is it expected to move a bit while you get things all buttoned up and glassed on the inside too?

Thanks in advance for the help!

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Jim Dodd
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Re: Movement From Forms Prior To Fiberglassing

Post by Jim Dodd » Wed May 16, 2018 10:26 pm

Welcome RustBelt !

This is a common problem, not really a problem, unless you want it to be.
Honestly, I doubt it will effect handling or speed.

I have on one occasion, with hot melt glue, attached a block to the inside keel, to pull a hull back down to the forms. I then anchored the block to the form. I glassed the hull, and the hull retained the correct shape. Again, I doubt it made a real life difference, but it did make me feel better !

My two cents worth !

Oh I live in the Rust Belt !

Jim
Keep your paddle wet and your seat dry!

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RustBelt
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Joined: Tue May 15, 2018 11:24 pm
Location: Iowa

Re: Movement From Forms Prior To Fiberglassing

Post by RustBelt » Thu May 17, 2018 10:01 pm

Thanks for the advice, Jim! You’ve helped all the way back to milling strips with a circular saw! Glad to hear from another Iowan on the board, too!

I had a feeling this was a common occurrence. I’m torn, but most likely I’ll try the hot glue/block approach you mentioned and see how it sticks. It sure felt like a big deflection when I discovered it, so my worry with pulling it down is having it warp or buckle over the cross-sectional profile. I’ve kind of witnessed this when putting on tie-down straps at a few of the forms. On the other hand, the forms give me the best shot at being accurate. I’m a designer by trade so I already have a tendency to be particular, and I’d hate to get it out to the water and have it list to port or something.

I’ll keep you posted on how it goes!

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Jim Dodd
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Re: Movement From Forms Prior To Fiberglassing

Post by Jim Dodd » Fri May 18, 2018 10:04 am

The Aim is to build true to the forms ! Not always possible, and that's when the McGyver in us is called upon. I learned the trick here. Thinking it was from Patrick's Dad ?

Where abouts in Iowa ?
I'm in Humboldt.


Jim
Keep your paddle wet and your seat dry!

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RustBelt
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Joined: Tue May 15, 2018 11:24 pm
Location: Iowa

Re: Movement From Forms Prior To Fiberglassing

Post by RustBelt » Fri May 18, 2018 4:47 pm

Yep, my thought was follow the forms. I'm assuming you're using the wood glue formulated hot glue sticks (like the Surebonder Wood Stiks)? Guessing that hold will shear right off with a well placed chisel and mallet without tearout? I haven't used hot (wood) glue in woodworking as much as I probably should have.

I think I'll use tie-down straps at each form to get it back to the forms, and place one block at the centerline of each form attached to the centerline of the canoe from Station 0 and out until I come across one without with a noticeable deviation. One block at the center might minimize any buckling across the profile by allowing the strips to fair, if it will hold when I ease off the tie-down straps.

I'm in Capital City (Des Moines).

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Jim Dodd
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Re: Movement From Forms Prior To Fiberglassing

Post by Jim Dodd » Fri May 18, 2018 10:17 pm

I'm not sure what Hot Melt glue I used, as it came with the gun.(I don't use it much)

I'm told Alcohol, loosens it, for removel.
I get to DesMoines once in awhile !
We'll have to hook up !

Jim
Keep your paddle wet and your seat dry!

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Patricks Dad
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Re: Movement From Forms Prior To Fiberglassing

Post by Patricks Dad » Mon May 21, 2018 9:08 pm

I use whatever is handy for hot glue. No need for super strong stuff (I cover my forms with packing tape so really strong hotglue would pull the tape off before it pulls off the boat). I don't tend to need very much to hold the hull to the forms. It usually just peels off by had or a scraper. Any residue disappears with the sanding.
Randy Pfeifer
(847) 341-0618
Randy.Pfeifer1@gmail.com

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RustBelt
Posts: 6
Joined: Tue May 15, 2018 11:24 pm
Location: Iowa

Re: Movement From Forms Prior To Fiberglassing

Post by RustBelt » Tue May 29, 2018 9:06 pm

Thanks Randy and Jim! Hope you had a nice Memorial Day! I’ll report back when I get everything glued up.

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