Butch Block

Product Review Article ...by Brad Mahs



Check out this hot product that will make stuffing tube installations a breeze!!!






Every once in awhile, I come across a product that makes me stop, shake my head and say "Man, that is so obviously simple! Why didn't I make one of those before?!"


This was exactly the case when I saw the machined aluminum stuffing tube mount block made and sold by Butch FieldsImage (ButchTheBoatMan on Jim's R/C Boat Dock). I was in the process of building an Offshore Models Teamstrike Supercat and was just about to plan the drilling and mounting of my stuffing tube in the conventional way: fiberglass it in place. But when I saw Butch's stuffing tube mount block, I knew that this was the way to go! I quickly contacted Butch and ordered one from him.



The Product


The stuffing block mount comes as a ready-to-install kit and consists of the following:

  • (1) machined aluminum block mount
  • (4) 6-32x1/2 pan Phillips head machine screws (S.S.)
  • (4) #6 S.S. flat washers
  • (4) 6-32 S.S. Nyloc nuts
  • (1) 11/32 brass guide tube
  • (1) aluminum installation guide rod (turned to fit in clamp collet)
  • (1) instruction sheet
  • (1) dimensional guide sheet


The kit cost $35.00, with shipping extra. A bargain, considering how easy it is to install and the time it saves! It arrived via US postal service a week after I had mailed Butch a money order. Great turnaround!


The mount block is machined from solid aluminum, with an 11/32 diameter hole bored through at a 14 degree angle. Butch also offers 6 and 12 degree angle models, and will do custom angles on request – contact Butch for details. Four mounting slots are machined to accept the stainless steel machine screws. Pretty simple stuff, really. The machine work is top notch! Mine had a good polish on it – this isn't normal however. Butch will polish them upon request for a I don't know if this is normal or not (editors note: contact Butch when ordering and inquire about polishing as an added cost). I touched it up with a little Mother's metal polish to make it really shine.


However, the real beauty of this kit is the addition of the brass guide tube, and aluminum guide rod. These two components make installation a breeze! The 11/32 diameter hole will allow the use of a brass tube with a Teflon liner, or a non-teflon 5/16" tube inside the short 11/32 guide tube.



The Install

Here's what was used to install the block:

  • Electric drill
  • 5/32 drill bit
  • 5/16 drill bit
  • Phillips screw driver
  • 5/16 open end wrench
  • Sealant (silicone, Goop, etc.)


ImageThe instructions are extremely thorough. But, they are written specifically for installing using Hypertorque style mounts, and involves finding engine placement, measuring, drilling and bolting up the rear engine mount points, then positioning the stuff block and mounting it to control the drilling location for the front engine mount points. I had made custom quick release vertical mounts, and knew exactly where I wanted the stuffing tube to go through the bottom of the hull. I'm pretty anal about measuring things to the nth degree, and had figured out exactly where each component needed to be to get the stuffing tube bend radius as gradual as possible. This required a slightly different approach to the installation of the stuffing block mount for me.


First, I marked the centerline of the tunnel on the inside of the hull, using a cardboard template as a guide. I highly recommend you do this step regardless of how you install this block, since it will help guarantee you have a perfectly centered stuffing tube installation! I also made a cross mark at the location where the stuffing tube needed to exit.




Next, I found the center of the aluminum guide rod and marked it with a line, slid it into the brass guide tube, placed them both in the aluminum block mount and marked the location where the line intersected the bottom of the block. This cross-line was transferred to the top of the block.


I placed the aluminum guide rod in the engine collet, inserted the rod into the brass tube and placed the assembly in the aluminum block.


ImageAfter placing the block in the hull, I centered it fore-aft and left to right, and marked the center of each slotted hole. I also verified the engine location (right on the money, I might add!) and marked the location of the engine mounting points on the rails. The engine was removed but the brass tube and mount block were left in place.

Using a 5/32 diameter drill bit, I drilled the four mounting holes through the hull. Make sure to use a sharp bit and very slow in-feed rate to avoid shattering and cracking the gelcoat!

The 6-32 machine screws are installed from the bottom of the hull, through the slots in the block and secured with flat washers and Nyloc nuts.





ImageNext is the nerve racking part! I inserted a 5/16" drill bit into the brass guide tube and drilled through the hull. Again, high rotational speed and veeery slow in-feed is necessary! When done, the gelcoat edges were touched up with a fine jewelers file.


That's it!! At this point, the stuffing block is installed. I still had to mount the engine, however, to assure that it aligned perfectly with the block.







The engine with aluminum rod attached was re-inserted into the brass guide tube, carefully tilted, and "played" fore-aft to be sure the angle was perfect, and alignment was true. Luckily, my original mounting point marks were perfect! I removed the engine, drilled the rails and re-installed the engine and all the mounting bolts.


I test fitted a 5/16" brass stuffing tube into the guide tube and the fit is like a glove! Inserting a flex shaft proved that alignment was spot-on, and slop free! As of this writing, I still need to bend the stuffing tube and install the flex shaft.

The final touch will be to waterproof the installation. This can be done by using silicone, Marine Goop or similar sealant under the block, or by simply applying a fillet of sealant around the base of the block after it's installed.


Total time for the install as I did it was 35 minutes! Of course, this didn't include the 47 hours worth of measuring I do when setting things up, but that's another story! LOL.



ImageThe Result?


The one component this kit lacks is a backing plate for the bottom of the hull. This would help distribute the stress the machine screw heads place on the hull, especially on a hull with a slight vee on the bottom (as with the TS SuperCat). Since the block is flat on the bottom, the hull wants to pull up to fill the gap when you start tightening the screws – I didn't torque mine too tight for fear of cracking the glass-work.


I later fabricated a thin backer from sheet aluminum for final installation. Alternatively, epoxy could be used whenImage installing the mount (using wax paper between the mount and epoxy) to fill the gap and create a firm mounting pad for the block. However, the backing plate works really well and allows the screws to be tightened a bit more without any deformation of the hull or cracking of the gelcoat. Butch will make you a backing plate for about a $5.00 fee. I strongly recommend getting one for any hull installation that isn't flat.


The angle is set at 14 degrees and is not adjustable. This block should work on most any catamaran, and possibly some hydros. Butch doesn't recommend it, but it appears that the mount could be shimmed by adding washers between the hull and block mount to gain or lose a degree of angle. I would definitely fill the gap with epoxy in this case. Again, the alternative is to simply talk to Butch and have him make you a custom angled block, if you really need it.

In my opinion, this is a must-have component if you're setting up a catamaran or hydro!!


New: If you are setting up a mono, see the Butch T-Bar !


Whether you don't want to hassle with fiberglassing the stuffing tube in place, or if you want to make the installation quickly and efficiently, this product allows for a clean, simple, fast, accurate and adjustable stuffing tube mount in less than 1 hour!


What more can you ask for?



For ordering information, contact

Butch Fields
Ph: 610-721-6559
This email address is being protected from spambots. You need JavaScript enabled to view it.



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