Vac-U-Soling Lower Hull Kit.

Manufactured by Vac-U-Boat

Coming soon.

Now that this lower hull kit was approved for the Soling1M Class, it will take a while to obtain materials and adjust processes for manufacturing kits.
In the meantime, we are making adjustments to molds based on feedback from building the trial kits to include building molds more suited to higher volume production verses a short-run of trial kits.

We anticipate shipping kits starting in late January. There is a list. No deposit needed. Just ask by email and you will be confirmed to the list. Email:

The Vac-U-Soling lower hull complete kit will cost no more than $200 + postage.
Standard parts like keels, rudders, hatch covers and crossmembers will be available for repair/maintenance/upgrades.
The kit will also be available without a keel, or with a different weight of keel at no additional cost as compared to the standard keel that is part of the complete kit.
Because the keel can be swapped out in a couple of minutes, the option of having a second rigged hull without keel as a backup is possible.
Having different weights of keels available to use depending on weather conditions is now practical.
The weight of a "standard" keel will be known soon once the updates are done and another trial kit is built.
A full price list will be posted before production.

This is NOT your father's Soling.


February 25th: Resin still not shipped from the distributor is in Texas (Snow storms). Made duplicate order to the manufacturer in PA today in case there are further delays.

Feburary 18th: Shot is here, only to discover that the liquid resin that I have has aged. It is used to make rudders and keels. Fresh resin was ordered earlier this week. Winter storms have slowed things a bit. All duplicate fiberglass molds are done. Workbench is cleared for casting keels and rudders as soon as the resin arrives. All other parts are done. Meanwhile, I'll continue to work on instruction changes.

February 3rd: Im still waiting on lead shot to arrive. Meanwhile, I tested two versions of the deck formed with lighter materials & built the latest version of the hull. I am working on changes to the instructions and will have updated ones posted soon.

Final-version hull weight: Including the hatch cover & magnets, thinner deck with full deck liner, smaller hull liner, thinner transom liner, thinner king post mount, lighter keel shoe & shelf reinforcements, two anchor point reinforcements, all deck hardware, wired crossmember, rudder mount, rudder servo mount, smaller battery tray, keel nuts & washers & 3 coats of paint, without keel, without rudder & linkage, without servos or other electronics, 2 pounds, 3.7 ounces. Add rudder, linkage & arm 2.4oz, receiver .4oz, sail servo + arm & screws (Bilda Torque) 2.8oz., rudder servo HS225BB .9oz., battery 1,200mAh 4.0oz., sails & rigging 9.0oz for a total of 3 pounds 3.5 ounces. With a 7.0 pound keel, total weight would be about 10 pounds 3.5 ounces

The trial kits were made with some hand-fabricated parts the same way you might make them when building a single boat for yourself. Custom plastic parts were copied using economical rubber molds and poured resin. While great for a one-off build, such methods are too labor intensive for the efficient production of boat kits. While we are waiting on more hardware bits to arrive, we are adjusting the process of making parts for the Vac-U-Soling kit. The goal is to make them lighter, stronger, and to reduce the labor necessary to produce them. We are also making adjustments to the vac-u-forming molds based upon feedback from the trial builds. Further refinements have been added such as taller ceramic deck fairleads and additional circuitry to the crossmember so you will see a blue LED light to indicate at a glance when the power is on.

For example:

Keel Shoes that were made from poured resin are now made with this aluminum injection mold. The result is a stronger keel shoe that weighs 60% less than the trial kit version. The same thing was done with the Hull Liner Reinforcements reducing them from .7oz. to .4oz.


Features include:

Removable fully completed 7 pound keel with options to special-order lighter or heavier weights, completed rudder with Du-Bro rudder arm, stainless pushrod and EZ-connector for your servo, self-aligning rudder mount, integral transom on the hull, no wood components, fiberglass deck cleat backers, pre-drilled self-centering keel mount fiberglass servo board/crossmember, stainless steel keel mount, stainless steel deck hardware, plastic mast step, magnetically attached hatch cover, removable carbon fiber king post, industrial-ceramic deck fairleads, tongue-in-groove perimeter deck joint to hull, full deck, partial hull and transom reinforcing liners. Crossmember accommodates sail servos from standard footprint high-torque digital models all the way up to the HS-815BB large servo. Rudder servo is mounted near the rudder or can be mounted on the crossmember. There are no bulkheads giving you better access to the hull's interior.  

Does not include paint, sails, mast, booms, sail rigging or electronics. We are working on developing a basic sail mast-rigging kit for release in the future.

Build instructions PDFs and a review by Alan. Click on the image to view.


I removed the Lightweight Build Guide. It is counter-intuitive to produce a boat kit that needs such a guide when the better choice is to make the kit lighter. There may be a revised guide later.

My kits are generally stout. They can survive being dropped or colliding with another boat. But that comes at a cost in weight which isn't so important for a scale or fast-electric model but can be critical for a sailboat.

To explore this, I'm applying some critical thinking to the materials used in the trial kits and making some adjustments that will bring the boat more in line with existing kits' weight and strength. The standard build instructions should yield a more competitive-weight boat without having to bash the kit to get there.

Thanks, Phil

Build Instructions as of October 27, 2020. 30 pages with over 350 photos.   Alan reviews his build of a prototype kit on YouTube.


Photos of the first prototype build:

Click on photos to enlarge.

Fully reinforced deck. No special tools required. Assemble with clothes pins and soup cans. Reinforced hull with integral reinforced transom.
Reinforcements can be trimmed to reduce weight. Deck cleats are backed with precut fiberglass board. Keel mount crossmember brace doubles as a sheet servo & switch mount.
Lightweight rudder servo mount aligns to prebuilt rudder mount. No bulkheads. No wood. Clean interior. Tongue-in-groove deck/hull joint for maximum strength.
Lots of room for bow access. Lots of room in the stern. Sail rigging can be as simple as this.
Clean deck with sheet adjustments. Stainless Steel deck hardware. Another example with standard footprint servo.
Tongue & Groove perimeter deck seam. Cross-section view from stern.  

Cross-section view from bow.