Scratch Build - 29" Balsa Stepped Cat
#51
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From: Centerville,
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That is my plan.[>:] Funny how far I've come with out a plan. I devised this one while attaching the skins. Seems like about the only way to do it.
#52
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From: Centerville,
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More progress on the balsa barge. First picture shows the sides after sanding down to the supports. I then used a template from the origninal stringers to cut the steps into the outside. A little more sanding and then glued the bottoms in place, more sanding. You get the idea. I'm real happy with it so far. THings will slow down as now I have to do the nose on the tunnel and the rear and I'm not sure how I'm going to do it. So more thinking. Starting to look like a boat now.
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From: Centerville,
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Thanks. Anyone have a recomendation for the best (lightest) floatation foam? I'm getting ready to urathane the inside of the hull and after that it's foam and put the top on.
. Has anyone used "Goodstuff" The expandin type of foam. It would fill it completely and since It's not enclosed yet I don't think that it would damage the boat when it expands. I'd just go sparingly and cut off the excess before putting the top on. I think it's pretty low density and probably pretty water resistant.
. Has anyone used "Goodstuff" The expandin type of foam. It would fill it completely and since It's not enclosed yet I don't think that it would damage the boat when it expands. I'd just go sparingly and cut off the excess before putting the top on. I think it's pretty low density and probably pretty water resistant.
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From: Centerville,
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I may just use the stuff that was in my SV's box. I think that's the same stuff they put in the bow of it. I replaced it with a thermo sealed bag of air (can't get lower density than that) but for this boat given the mutiple bulkheads I'm going with foam.
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From: Centerville,
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Update: Have finished the transom. I will likley modify the vertical radii that are on the back of the stringers. These are different than either of the similar boats that I have seen including the finished product of the original designer, and I'm not sure of their intended purpose. I pretty much designed these as I went. (made one, liked it and duplicated it). I'm very happy with how it came out. I need to finish the nose on the tunnel and then things will really pick up.
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From: Centerville,
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Taylor,
No I didn't soak but that's a good question. That's partially why I added the flat area because I didn't think I could make the bend without it. The flat area made for a larger radius and less bend. I did some test bends to try to make the full radius that ended in a "pop". With this design I did it (bending with the grain) with no problem. I may run in to problems later as I plan on "armoring" the whole boat with 1/64 ply. I don't know how that bends but I assume not as good as balsa. So if you soak it, just water? Then you bend and hold and let dry before you instal? I'm learning stuff every day here.
No I didn't soak but that's a good question. That's partially why I added the flat area because I didn't think I could make the bend without it. The flat area made for a larger radius and less bend. I did some test bends to try to make the full radius that ended in a "pop". With this design I did it (bending with the grain) with no problem. I may run in to problems later as I plan on "armoring" the whole boat with 1/64 ply. I don't know how that bends but I assume not as good as balsa. So if you soak it, just water? Then you bend and hold and let dry before you instal? I'm learning stuff every day here.
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From: Centerville,
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Good,
I haven't purchased any of the ply yet. I'm solving one problem at a time. Just going off of shockerman's experience on using the 1/64th ply. I know I don't want to run with any of this balsa exposed, accept maybe the inside of the tunnel. Pretty delicate stuff.
I haven't purchased any of the ply yet. I'm solving one problem at a time. Just going off of shockerman's experience on using the 1/64th ply. I know I don't want to run with any of this balsa exposed, accept maybe the inside of the tunnel. Pretty delicate stuff.
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From: Poughkeepsie,
NY
ORIGINAL: SV27dayton
I may just use the stuff that was in my SV's box. I think that's the same stuff they put in the bow of it. I replaced it with a thermo sealed bag of air (can't get lower density than that) but for this boat given the mutiple bulkheads I'm going with foam.
I may just use the stuff that was in my SV's box. I think that's the same stuff they put in the bow of it. I replaced it with a thermo sealed bag of air (can't get lower density than that) but for this boat given the mutiple bulkheads I'm going with foam.
I'd stay away from any spray on foam. It might not crack the hull, but it could deform the hull and I dont think it will be very light.
#65
Spray foam will also absorb water and eventually make a mess of the hull. I mainly use pink insulation foam, or the gray pipe insulation foam.
Ryan
Ryan
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From: Centerville,
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OK,
I now hate spray foam. I'll never use it. Thank you for saving me from trashing my project. As for the coating I'm planning on using an oil based urathane inside and out. Hull we likely never see any paint.
I now hate spray foam. I'll never use it. Thank you for saving me from trashing my project. As for the coating I'm planning on using an oil based urathane inside and out. Hull we likely never see any paint.
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From: Tottenham/Orillia, ON, CANADA
here is a hack job of what i did on one of my boats . I just glued odd pieces i had from a sponson job. it will do the job
#68
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From: Centerville,
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I guess that's as good as anything. It' not like anyone's going to see it. Unless you take pictures of it before putting the top on and post it on teh web
. Do you use a ply coat on the outside or are these not balsa to begin with? What do you typically build with? What are you using the coat the hull? Looks clear, shinny and slightly tinted. I like it.
. Do you use a ply coat on the outside or are these not balsa to begin with? What do you typically build with? What are you using the coat the hull? Looks clear, shinny and slightly tinted. I like it.
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From: Poughkeepsie,
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At least you made me think of how much I need more foam in my boats. I'd really like to avoid the incidences I had last season. I think now I'm going with that pink foam, then I can keep my beer cold....
off topic, but on a long boat trip my father modified a cooler to keep a block of ice for 2 weeks, without refrigerant. Pink and blue foam is great.
off topic, but on a long boat trip my father modified a cooler to keep a block of ice for 2 weeks, without refrigerant. Pink and blue foam is great.
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From: Hudsonville,
MI
I use epoxy to coat mine, some people use laquer, some use polyester resin. My question is can i use [link=https://www.hardwareworld.com/Pt-Polyurethane-Gloss-pYB7M4P.aspx]this[/link]to seal the inside of my hull. What about the outside?
#71

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From: Tottenham/Orillia, ON, CANADA
Scott. the frame is all 5ply 1/8th and the skin is 5ply 1/32nd with a 1/16th hull and hatch
that is all west system on that boat.
that is all west system on that boat.
#72
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From: Centerville,
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Is that a seam on the side? If so are you cris-crossing the grain patterns? I'll have to have seams if I do this because I cant find the wood cut both ways. I figure with ply they've already done that so it shoudn't make a big difference. I'll probably run it whatever way creates the fewest seams. I think it will be pleanty strong.
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From: Centerville,
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How much weight will the epoxy/glass add. How doest the glass go on? Is it just the fiberglass resin or is there reinforcement in it?
#75
Glassing the hull will not add a lot of weight when done correctly. Lay the cloth (something around 1oz cloth) out on the hull and then spread the epoxy over the glass and push it in. I actually use a popsicle stick for this. When done scrape away as much of the excess epoxy as possible. This will reinforce the hull and provide a waterproof layer.
Or
Just use a coat of epoxy mixture over the bare wood to seal the wood. Adds less weight but no reinforcing, just the waterproof coating.
Ryan
Or
Just use a coat of epoxy mixture over the bare wood to seal the wood. Adds less weight but no reinforcing, just the waterproof coating.
Ryan



