Wee Nip

Hi all, hope everyone is safe and well. I have just ordered a Wee Nip kit plan and dvd from Sarik. It looks to be a straight forward build. I am going to get a sail rig from Housemartin Sails but am stumped when it comes to a keel bulb. Is there anywhere that can supply one? Alternately I am thinking along the lines of a 3D printed shell filled with shot. How have other folks done it?
Cheers all...

I would not bother with a 3D printed bulb you just cant get the weight required using shot. Better to laminate layers of flashing epoxied together and files to profile.

PS. Plenty of info here http://www.weenip.org.uk/

Here’s my build lot on my wee nip!

https://www.thercmodelboatforum.com/t887-wee-nip-build

Sail was built from scrap ( its really easy) so save some penny’s, the masts and boom are carbon fibre rods...

But the kicker the keel bulb is actually home cast by my old man he simply made a plug cast it into some plaster to give him the negative, heated lead with a blow torch poured and cooled, popped the half out, repeat...

Sand the backs almost flat and file the keel slot.

The two half’s were then bolted together through the keels, p38  and painted...

I ordered the plans yesterday, but by the time they get here I will be probably tasked with a honey do, so I started building from scratch.
I couldn't find the offsets anywhere, so I scaled up the plan shown in http://www.weenip.org.uk/design-overview.html to match exactly 700 mm LOL and used my old dolphins and a spline to create a second degree curve for the deck profile.  If anybody wants the offsets I obtained, just let me know.
Made the deck out of 3 mm plywood and will do the bottom and sides out of 1/8" hard balsa (that's what I have in my bin of scraps).
Here is a picture of the deck construction:

This is my wee nip build, 1 of 3 I did.. my show version I guess, it might help with a few technicals down the road


https://www.thercmodelboatforum.com/t887-wee-nip-build

Thank you.

Welcome to the forum you have a ridiculously tidy desk! I'm envious.

Anybody does or knows who makes lead ballasts for the Wee Nip?

Sorry I have no clue who makes them.

Ours were scratch cast for the plans to make a plug, we just melted a roll of roof lead flashing and cast two half’s which we epoxied and bolted to the keel.

It wasn’t that hard to do a bit of light casting, forming the plug was done with layers of ply which then were p38 and sanded to final shape and smooth. The plug made the negative half’s in some plaster, making them singular use for each cast. A roll of roof flashing made 3 sets in the end.

Actully the worst part of that was filing the slot in both half’s for the keel, cost damn... lead

Thank you Roadrunner.
I used to cast my own bullets and still have a lot of lead somewhere in the garage.
I was considering doing the half mold/plaster as you did, but then considering also doing a plain squarerish cast with the aluminum keel embedded during the cast.
The other alternative is doing a lost wax mold.  I've done it before but only with some small jewelery pieces but I gave away the centrifuge and the muffle furnace.

As I write this post, I continue pondering what to do and I think I'm going to go with the half mold/plaster technique. 

I pulled out the dimensions from the plans and it is a huge piece, 28 mm diameter and 281 mm long.  I wonder how much it is going to weigh.

Four days ago I received the plans and the DVD from Sarik (Hurray for the Royal Mail).
I discarded the hull I was making and started again by using the plans. I have cut all the plywood parts already, so I'm ready to start assembling it.
Before starting the assembly, I will cover the inside surfaces with epoxy.
Pictures to follow.

1.4kg I think top of my head

The process is not difficult for modelers.  First thing is to determine the size that you want.  Lead weighs 720 pounds per cubic foot.  That means that each cubic inch of lead will weigh 0.416 pounds.  

The first part of the deal is to whittle a replica of the bulb that you wish to make.  Finish sand it carefully and use paint or epoxy to seal it. Now cut in half, down the centerline.... A light coat of oil or PVA parting film is a good idea.

Place the half plug on a piece of flat sheet metal or other flat iron or metallic sheet or plate. In fact you can do it with a large frying pan if the wife does not catch you doing this project.     Make a box with no top or bottom. Just four sides. Place the half plug flat side down down on the wax paper with the box surrounding the plug, with space to spare, maybe two  inches or 5 cm separation from the plug. Mix some plaster of Paris and pour it into the box over the top of the plug. Pack it down with your fingers and hands.

OK..... so now we have the mould.  You need to let the plaster dry thoroughly before the next step.. You are going to pour molten led into the cavity when you have removed the half plug from the plaster.  If the plaster is even slightly moist DO NOT POUR LEAD.  The lead is dangerous in that it will pop and splatter molten lead out of the Mould if there is any moisture present.   Be careful this is the dangerous part. You can cook the plaster in your kitchen oven at a low temperature perhaps 150..... 175 F  If you are impatient.  Make damned sure it is dry in any case.

You can get lead from various sources.  One of them is at the tire shop where they will have a lot of used wheel weights. Or consult an ammunition reloader.......or perhaps the roofer.  Sheet Lead is often used as flashing for chimneys and other places.

Lead can be melted on an ordinary electric hot plate.  Use a tin can or your mother in law's sauce pan.  Melt the lead and you will see some junk on the surface. That is dross.  Skim it off with a stick so that you have clean lead.  Now stop to think about how you will transport the hot lead to the mould.  This part can also be dangerous if you fail to plan ahead.  You must do the transfer quickly because the lead will freeze in just a few minutes.   Pour the lead into the mould and go have a beer or whatever you wish to use for a celebration. Give the lead several hours to come back to ambient temperature. Extract it from the mould and do the whole process once more. The lead will shrink a tiny bit when cooled, so it will pop out of the mould readily.

This is not a big deal if you are careful and heed the warnings above.
.

Two years later and I finally finished my Wee Nip.
Made the mast and boom out of aluminum arrows.  The sail out of ripstop nylon.
The keel bulb was a major job.  First, I carved the bulb out of bass wood in two halves.  With it, I casted a plaster mold and had to wait a couple of weeks for it to dry.  The lead casting part was not hard but dicey.
Today W N got its first sea trials.  It had problems with the sail control.  I think I found a solution.  Tomorrow wil continue the trials.