transom brace and other items

I am building a US1M boat from a set of plans from amya, I believe its called the Magic. Well I started planking today and well ran out of CA and no stores open!!! So I started reading ahead and have the following question(s):

How wide should should the transom brace be? The construction guide says use 1/8 inch plywood (if i am not mistaking)

What angle should the transom should be cut? I see no reference anywhere saying this or anything like “1 inch aft deck place transom brace and mark/cut down to the end of the keel plate…”

Last question,

Does anyone recommend someone for casting a 5lbs lead bulb? I have some diving weights I can ship them (if they are usuable for casting) Lead casting is strictly prohibited (spelling?) in my area.

thanks for the time.

Great Basin and GRP have lead keel bulbs, casting lead is something best left to experts. I hear regularly about industrial “accidents” at places near work, and they are “pro’s”. For the transom try about 45 degrees or whatever looks best, the waterline should ideally just touch the back edge of the transom of most designs. 1/8" lite ply or a sandwich of 1/64" ply, 1/16" balsa, and 1/64" ply. Or if you want to go cheap 1/8" luan doorskin.

What’s a transom brace for? I usually just have a doubler.

i think what he is refering too . is a transome spacer/outerbulkhead. you see them on the skiff design boats. like a ts3 and disco. think of it as a the back end of the boat. but with the middle. i cant explain it right but if you look at a ts2 stern. it does have a transome. it is just very small. and that is what i am thinking he is talking about
btw i use1/8 plywood . that has been coated with epoxy

Hi Drake…
In the USOM construction guide, that you can download from the AMYA website (same page where you got the Magic plans…) there is a chapter (few pages, with pictures) dedicated to the transom brace, all that you need to know is there. As for placement, if I remember correctly, there is a template for it on the Magic plan, just fit it (before you take out the last shadow, so not to warp the hull) .
As for the lead bulb…. Buy the already made one much easier and safe.


EDIT: Sorry I went to check, the magic plans don’t have a template for the transom brace…. It’s a straight one. In that case the placement is up to you, where you think it would look good. As long as the boat is 1 meter long

i’ve made some bulb molds and casted a few bulbs, and it’s not easy. Molten lead is realy hot and you gotta be very careful when handling it. The lead smoke smells bad too. Then you gotta be aware of how much heat it carries and not to let the heat get at the workbench.

Thanks everyone for your input.

I think I am going to put the Transom brace so that its gives me a 30’ transom (correct term? i don’t know,)

As for the lead bulb, i contact GB and they told me to go ask GRP (but they atleast told me they wil lsell me a package deal for the rigging!!) I am waiting for a reply from GRP If possible I wil lget the CF fin and the 5lbs bulb from them… if they ever respond…

Another question, whats the best way to sand down my hull once i have finish planking? block sander, sanding in every direction but down the length of the planks? Would my handheld hander work with a finner grit? (say 120-200?)

I will post all my pictures from start to finish of the planking once I am done sanding :slight_smile:

thanks once again

Sand in a diagonal direction with relation to the waterline, be very careful not to remove too much. The last time I planked a hull the planks ended up too thin, even with glass cloth the hull was too easy to push in. Use a block and 150 grit sandpaper. Keep the vacuum handy, take your time, sand a little, vacuum, feel the surface with your hand, take your time. Did I mention to take your time?

regardless of what the plans call for, I would personally advocate for vertical. I watch a lot of the boats in my club with angled transoms. When they start sailing up wind in a breeze (heeled over) they loose waterline due to the slanted transom. you can actually see that this causes turbulation where the water flows off of the stern. Keep it vertical and keep the waterline. slanted transom does look better though.

Just my opinon.