Welcome to the second interview conducted by International Waters.  For the February edition,  John Finch has agreed to speak with us about how he got started in R/C boating, as well as the "black art" of prop modification. 

Readers of Radio Control Boat Modeler will be familiar with the name John Finch from his many articles, reviews, and Nitro News columns.  Before our interview actually began, I asked John to give us some background information.  Basically, I asked him what he was most proud of in regard to his R/C "hobby" so that I could provide an interesting introduction before the questions began.  However, instead of me trying to capture the essence of one of the longest and most successful R/C boating careers in a few sentences, I'll let John speak for himself: 

When I was seventeen years old, a guy by the name of Frank Blanchard made his garage and tools available to me because I had no garage to work in.  We often talked about the need for information on the hobby, but there was no place to go for help.  Flying Models Magazine had a page or two at the end of the magazine for boats, but that was all that was available.

A couple of years later, a friend of mine by the named Pete Vack, who liked to write, suggested that we co-write an article for Flying Models Magazine.  We did an article on one of Frank's Lauderbach scratch built boats.  I continued writing for the publication for quite some time while Pete took off in the direction of his love: exotic cars.  The magazine was the perfect tool to let thousands of people into my garage just like Frank did for me.  In 1987 Air Age publishing introduced American Boat Modeler Magazine.  I caught wind of the magazine, called Louis V. DeFrancesco, the publisher, and offered my services.  In 1988 Louis asked if I would be interested in writing a book for the beginning model boater.  It was a dream come true!  I would have to get a bigger garage!  I have now written over seventy five articles for R/C Boat Modeler Magazine and three books through the team efforts of Air Age Publications.  Being able to help the model boater through these writings gives me the greatest satisfaction of all my accomplishments.

Another accomplishment I am proud of is having three records in the I.M.P.B.A. mono class at over 70 mph.  Breaking the 70 mph barrier was a tough one.  It took countless hours on the bench and at the pond.  I tested concepts, boat design, props, and hardware to the degree that would send anyone to the nut farm.  I just got my E and F mono record certificates last week for establishing new record last fall.  The F mono record is a shared record with a friend of mine named Kently Porter.  We used his engine in my boat for a team record of 73.481 mph!  Since then, the boat has been clocked at 80.2 mph on the stalker radar gun.  Other accomplishments include being club president and secretary for several clubs, being District director for I.M.P.B.A. and most of all being inducted into the I.M.P.B.A. hall of fame last year at the Internats.

OH... Almost forgot!  I was the founder and designer of the Twin Craft line of model boats.  After five years of business, it grew to a point where I had to either quit AT&T or give up the boat business.  AT&T was my livelihood, so I gave up the business.  I gave it to my best friend, Steve Speas, knowing it would be in good hands.

John Finch:  I was seventeen years old and flying model airplanes when I was first introduced to model boating in 1968.  A friend, Ron Coffee and his buddy, Adison Clark, were running boats at a local pond and invited me out to watch.  They were fierce competitors on the water and the best of friends off the water.  I drove one of their JG fiberglass hydros and was hooked! 

I bought one of Ron's old shovel nose hydros and a McCoy 60 red head engine.  I was so eager to run it that I went to the pond on a Freezing cold day in February.  My dad was there as always to help and he got the boat on his eight mm movie camera. 

IW:  There are a lot of people getting involved today in R/C Boating that look to you as sort of a mentor or role model.  When you were learning the ropes, who helped you along? 

JF:  If I had to single one person out as my mentor it would have to be Frank Blanchard.  He offered his garage and tools with an open door policy.  If he was home, I was welcome to come by and work on my boat.  I learned a lot from Frank about life as well as boats. 

IW:  Can you give us an estimate of how much time you invest in a hull (building/tuning) before it's ready for a major race? 

JF:  I have different scenarios that I follow in preparation for a major race, depending on what I wish to accomplish at the race.  Sometimes I go to win, sometimes I go to just have fun, and sometimes I go to experiment with a new boat or concept.  I frequently do all three at the same race.  I will run one boat that I have paid the dues on, one that is an experiment, and one that is an average boat where I am challenged to drive well in order to win.  Doing all three gives me different challenges. 

Preparing a boat to win requires the most preparation.  It might take two days or two weeks to build a boat, but paying the dues is the hard part.  Paying the dues, as I call it, is going to the pond several times to try different props, pipes, engines, and different hardware setups.  It is going back to the workbench after each day at the pond, thinking about what worked and what didn't.  Then, it means going to at least two local races to confirm the setup and get used to the handling characteristics of the boat.  Time spent paying the dues can be three weeks or three years. 

When it comes to record trials, the dues are very high.  When someone breaks a record it looks easy, because you didn't see them pay the dues, you only see the rewards.  When I prepare for a record trial, I get to the pond at dawn and leave when the sun goes down.  I commit to at least one day every week for months in advance.  One of the keys is to team up with a good buddy and go to the pond when no one else will be there.  Not for secrecy sake, but so you can concentrate without distractions and have clean water to work with. 

IW:  You mentioned that you try several props as part of preparing a hull to win.  Do you tend to run props that are "stock," (unmodified) or do you take the time to tweak a prop to a given hull? 

JF:  I first try five props that are all different in design but the same basic pitch.  I then take the prop design that worked best on that particular boat and refine it.  I bend the trailing edges five thousandths of an inch at a time until the engine runs in the rpm range that the boat is most efficient.  The tuned pipe must be set to this rpm as well. 

IW: How important of a role do you think prop modification has on the overall performance of your boat? 

JF:  I have seen prop modifications give anywhere between one mph and ten mph difference in a boats speed. A stock prop might be the best prop for a particular model while on another model you might gain an extra 10 mph by cupping the trailing edge.  In most cases a little prop tweaking will give you the edge in a race. 

IW: Do you feel that today's modeler overlooks prop modification as a means to a faster, better handling boat? 

JF:  Yes! Most modelers are scared to bend their props because props are expensive and they don't want to mess them up.  When they do bend props, they tend to bend too much and in the wrong places.  One ruined prop is enough to keep them from trying again.  The serious racer will learn to bend props or will pay the price to have someone do the prop work for him. 

IW:  Okay, then maybe we can help them out by laying out a few basics.  When you sit down to work on a prop, what tools are in front of you? 

JF:  I assume we have already sharpened and balanced the prop.  So .... I would need a pitch measuring device such as the Hughey, Steve Muck, or Little Rock Welding gauges.  I use all three.  I would need a pair of pliers with rounded edges so as to not mark the props when bending them, and I would use a ball anvil from Little rock welding in certain cases.  You need a small hammer if you plan on using the anvil.  I would have two screw drivers with the ends cut off.  One with a 3/16 shaft and one with a 1/4 inch shaft. The screwdrivers are used to hold the props when I bend them. Also, a dial caliper is needed to make measurements in thousandths of an inch.  Most important is a pencil and paper to write down the measurements. 

If I was to duplicate a prop with one of Martin Davis's prop duplicators, I would have it on the table as well. Martin is the man behind the prop duplicator and is a great resource for prop duplication.  (His web site is [http://www.rcboat.com]). 

IW:  How does the choice of propeller material (Beryllium Copper, Stainless Steel, or Aluminum) affect its ease of modification?  What material do you prefer? 

JF:  Beryllium copper is the easiest to work and my personal choice.  Stainless is very hard, which makes it difficult to work with. 
  
IW:  How do you decide where to bend the prop? 

JF:  Prop bending is a black art.  I learned mostly from trial and error.  More error than success I assure you.  Again, Marty Davis has some good info on tweaking props.  I prefer using small props that I can add pitch to by adding cup at the trailing edges.  It's really not adding pitch, but directing the prop thrust cone more rearward.  The water shoots off the trailing edge with more authority.  I cup the trailing edges of the prop from about 1/3 rd up from the hub to the tips.  I take several measurements along this path and grab the trailing edge of the prop at about 1/4 inch in from the trailing edge to bend a little cup into the prop. 

Sometimes I use props that are too large and end up cutting the prop to change the blade shape and reduce the amount of water thrown off the prop.  Re directing the trailing edge by cutting it back at the hub can relieve the prop and reduce lift.  So, the area where the prop is bent or cut depends on what I am trying to accomplish. 

IW:  When you test a boat, what types of things do you look for to help you decide if you need to start with a smaller prop and "cup up," or with a larger prop and "cut down"? 

JF:  On lightweight hulls, large props cause the boat to lean over hard to the right because or torque.  The effects of torque are reduced by using small diameter props, so I cup smaller diameter props on light boats. 

When I run a heavy boat, the larger prop is the proper choice.  Small props on heavy boats tend to blow bubbles rather than get down the road.  The large prop slips less and gets the job done. 

IW:  Do you have any interesting projects going on right now that you could share with us? 

JF:  I am working on a hydro project with a good friend, Kently Porter.  Our goal is to run 100 mph with a hydro.  We have been working on the project for about a year now and we have finally realized that goal.  Yesterday we spent nine hours at the pond and when we left, Kently's 80 powered boat had done 103.4 on the Stalker radar gun and my 67 boat had been clocked at 103.6!!!!!!!  We plan to go to Huntsville Alabama in nine days [Editor's note:  around February 20th] to make an attempt to get the IMPBA 60 and 80 straightaway records.  We hope to be the first boaters in IMPBA to be recorded officially at 100mph. 

IW:  Last Question: Peer into your crystal ball and predict where this hobby/sport is going. What is going to be the next big thing? What technology should we be on the lookout for? 

JF:  I don't foresee anything spectacular in my crystal ball. Unfortunately, the hobby is not something that just anyone can do.  kids are our future, and they have too many other things that catch their fancy these days. 

Your guess is as good as mine on what will be big. It seems that model boating is a steady same old thing kind of hobby.  We re-invent the wheel about every ten years.  I would look in the direction of turbine power plants. 
 

Turbine driven R/C powerboats?  Forget the performance ... can you imagine what that would sound like!?  We would like to extend a hearty THANK YOU to John for making time for this interview through a very hectic schedule. I know I certainly learned something about props here and hop you did too.  I probably count myself amongst the number of modelers afraid of prop modification simply because I'll probably mangle my first few attempts.  But, on the other hand, it's probably something we all should consider looking into more often.