LM 18 with Tunnel Build - Texas

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pee wee
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Re: LM 18 with Tunnel Build - Texas

Post by pee wee »

GrantL wrote: Thu Jan 13, 2022 11:14 am Pee Wee -
- So do you recommend drilling small holes through all 3 transom layers and fitting either a nail or small dowel rod while the pieces cure?
It doesn't really matter which way you do it, before applying glue you could nail a couple finish nails from the top into the one below, fit the nails back into the same holes once glue is on. Pull them once the glue has set. Or you can fit dowels extending from the bottom layer through the next layer. If you glue them in, just leave them. If you didn't glue them in . . . :lol: just leave them!
Once they cure, do you pull it out and fill in with epoxy resin? I'm using the Gel Magic, will i still need the vent hole for this product since its a little thicker than normal resin? You don't have to use a vent hole, but it would be just as useful for Gel Magic as thickened epoxy. No need to go crazy with them, but a couple will give you peace of mind that you've got enough weight on there.
- And noted on the vent hole, very helpful, is that only for the top piece or for all three in same spot?
The vent hole(s) would be in whatever is the top piece you're gluing, I wouldn't recommend doing all three at once.


Hank

GrantL
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Re: LM 18 with Tunnel Build - Texas

Post by GrantL »

pee wee wrote: Fri Jan 14, 2022 9:50 am
GrantL wrote: Thu Jan 13, 2022 11:14 am Pee Wee -
- So do you recommend drilling small holes through all 3 transom layers and fitting either a nail or small dowel rod while the pieces cure?
It doesn't really matter which way you do it, before applying glue you could nail a couple finish nails from the top into the one below, fit the nails back into the same holes once glue is on. Pull them once the glue has set. Or you can fit dowels extending from the bottom layer through the next layer. If you glue them in, just leave them. If you didn't glue them in . . . :lol: just leave them!
Once they cure, do you pull it out and fill in with epoxy resin? I'm using the Gel Magic, will i still need the vent hole for this product since its a little thicker than normal resin? You don't have to use a vent hole, but it would be just as useful for Gel Magic as thickened epoxy. No need to go crazy with them, but a couple will give you peace of mind that you've got enough weight on there.
- And noted on the vent hole, very helpful, is that only for the top piece or for all three in same spot?
The vent hole(s) would be in whatever is the top piece you're gluing, I wouldn't recommend doing all three at once.
thanks Pee wee for your comments on the transom. What is the issue trying
to do all 3 pieces at once? just too much opportunity to slide around?

and for the vent holes, do you do a couple tiny ones? like 1/8 inch? or
less? and are they spaced randomly throughout the top piece?

pee wee
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Re: LM 18 with Tunnel Build - Texas

Post by pee wee »

There's nothing technically wrong with doing both at once, but that would be a handful. I'd at least let the first layer set up and then follow with the second glue-up. The advantage with doing one layer at a time would be the opportunity to use the vent holes and observe that each layer has provided ooze out, while if you've got three layers you won't know what's doing what. Further, it will take some time to do, what with neat coating both sides, then use a notched trowel to spread out your glue, then assemble and if you're doing all layers then you'd have to get the next ones done before the first layer has begun to thicken . . . no, I'd say don't try to do it all at once.

I'm not sure how big your transom will be, but if you have two or three holes scattered over the central area that ought to suffice. A bigger boat might benefit from more holes. I don't know what the ideal size would be, but one eighth sounds a bit small; the idea is that when you see glue (Gel Magic) oozing up through the holes you can assume your panels are tight enough together for an even and strong lay up. If you don't see any glue squeezing out the holes, then add more weights because maybe you've got voids. You don't want to squeeze all the glue out, but some glue squeezing out tells you it's probably all solid. I don't know what you've got for weight, but try to spread them out evenly.
Hank

GrantL
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Re: LM 18 with Tunnel Build - Texas

Post by GrantL »

pee wee wrote: Fri Jan 14, 2022 12:38 pm There's nothing technically wrong with doing both at once, but that would be a handful. I'd at least let the first layer set up and then follow with the second glue-up. The advantage with doing one layer at a time would be the opportunity to use the vent holes and observe that each layer has provided ooze out, while if you've got three layers you won't know what's doing what. Further, it will take some time to do, what with neat coating both sides, then use a notched trowel to spread out your glue, then assemble and if you're doing all layers then you'd have to get the next ones done before the first layer has begun to thicken . . . no, I'd say don't try to do it all at once.

I'm not sure how big your transom will be, but if you have two or three holes scattered over the central area that ought to suffice. A bigger boat might benefit from more holes. I don't know what the ideal size would be, but one eighth sounds a bit small; the idea is that when you see glue (Gel Magic) oozing up through the holes you can assume your panels are tight enough together for an even and strong lay up. If you don't see any glue squeezing out the holes, then add more weights because maybe you've got voids. You don't want to squeeze all the glue out, but some glue squeezing out tells you it's probably all solid. I don't know what you've got for weight, but try to spread them out evenly.
Thank you sir! will do one at a time for now. using some drywall screw to fasten pieces together and will drill the vent holes.

I saw you mentioned a ridged trowel to spread glue.... i was using a dense foam roller before hand. do you think it will work for this transom or is a notched trowel the way to go?

Assuming the glue doesn't need to be layed on too thick but a needs to have a little thickness to it to fill in any uneven voids? thanks!

pee wee
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Re: LM 18 with Tunnel Build - Texas

Post by pee wee »

I don't like the drywall screw approach because while they pull, they might also hold the panels apart. I like weights better because they keep on working after you step away. The goal is to get an even coat of glue between the panels, I've heard people say a millimeter thick, but I'd think less than that. I guess rollers would work for spreading glue, too! As long as you get enough on there and it's spread around evenly and there's no big air pockets you're good to go.
Hank

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Re: LM 18 with Tunnel Build - Texas

Post by Fuzz »

I really like using wood dowels to line things up. Makes it easy to keep things from sliding around. Taper the tops so it is easy to get them lined up.

GrantL
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Re: LM 18 with Tunnel Build - Texas

Post by GrantL »

thanks everyone for the tips on prepping the transom pieces. I ended up using the dowel approach and was very pleased with it. I glued two of the transom pieces together tonight with Gel Magic and will let sit overnight.

Few questions for those familiar with Gel Magic or just transom gluing in general. I used 12oz total of Gel Magic (resin + hardener) to glue two of the transom pieces together.
- Do you think that was enough? i was surprised how much the transom took
- I only applied the gel magic glue to one side of the transom pieces and then joined the other piece together with the side that had the gel magic on it. I did this
because i was out of gel magic and didn't know if i had enough time to make another batch before it started curing. Do you think applying glue to only one side before joining
the two pieces is a cause for concern?


I used quite a bit of weight on the pieces after they were set but i did NOT have any glue seep out of the vent holes. It got me nervous i might not have used enough? Anyways, when applied with a trowel, i tried my best to evenly coat the transom piece, but now worried, i didn't use enough. Any thoughts or advice to test it out after curing or just opinions on how much you feel is enough or if i should be concerned? Thanks again for all the help and words of wisdom!
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pee wee
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Re: LM 18 with Tunnel Build - Texas

Post by pee wee »

If you didn't have any squeeze out around the sides or out the holes, you didn't use enough glue. It's possible you used the exact right amount that filled everything almost to the point of squeeze out, but how can you be sure? Did you neat coat both pieces with epoxy before spreading the Gel Magic? If you want to know for sure how well it's done, take a hole saw and cut a sample from the transom. Post a photo here and let the guys see it. After looking at it you will either start over (that would suck, but it's better than forging ahead with a weak part) or glue the piece back in and keep going, with the assurance it's solid.
Hank

TomW1
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Re: LM 18 with Tunnel Build - Texas

Post by TomW1 »

Is that all the weight you used with none on the corners? If so you needed more weight on the two corners that have no weight on them. What type of trowel did you use, a toothed one if so then you did not get enough to go both ways in opposite directions on each board. If you used a solid straaight edge trowel did you leave any low spots that would not provide a good bond. Then do as peewee said and make a 5 hole saw cut outs 1 from each qarter and 1 from the center. If there is one thing you don't want to fail it's the transom.

Tom
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GrantL
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Re: LM 18 with Tunnel Build - Texas

Post by GrantL »

Thanks both for your insight. I decided to reset and re-cut the transom and glue it again. i found some more gaps near the edges in between the 2 pieces (could slide a piece of paper up to 1 inch in between the pieces). Coupled with what Tom and Pee Wee mentioned, i decided to buy a sheet of Okume plywood, re-cut and re-glue.

3 questions-

- do you lay glue in opposite (90 degree) directions on the 2 faces you're gluing?

- if 12oz of total glue wasn't enough is there a good rule of thumb for oz/area of wood? (transom only)

- any better recomendations on ways to set the pieces once glued and weight down corners better? other than just using more random weights around the piec?

Lastly, and most important, i bought a new sheet of 4x8 marine okume (9mm), it looks like the individual plys are different thickness paterns than the sheets sent in the CNC kit. is that an issue as long as the total width is the same? (which it is)...... see pic below, bottom is CNC kit, top is sheet bought today from hardware store
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