ML Boatworks GS480 "L&L special" Gas Outboard Tunnel kit-Build thread

[Mike Luszcz]

For those that have had the chance to see the prototype gas outboard tunnel that Buddy Lowe has been driving for the last year or so, will enjoy seeing, and knowing that prototype has found itself into a kit form, or can be build by myself at ML Boatworks. This was a joint effort by Dick Loeb and myself. Dick had design ideas he wanted to use, and I helped finesse those into CAD. The excellent promise it has shown since its inception has led me to layout an easy-build kit for those that like wood over foam, but also like the kit to offer a little guidance of its own. You will find toy tabbing to help lock parts together, low weight crossmembers in the sponsons to help guide you threw building the sponsons as they were designed. As you know, gas tunnels have had the reputation of not turning well, or not running fast enough for their size. This hull breaks that mold, offering the user excellent turns while running some of the best speeds out there. I am sure you have heard that before..Ask some of those who have seen this hull run, they will back me up! The gas tunnel also paved the way for the PS295 FE 29.5" tunnel that currently holds all 3 IMPBA records, the QS370 FE 37" tunnel that holds the IMPBA SAW record and a 72.5mph one way pass, and the NS295 Nitro 29.5" tunnel that has propelled Dick Loeb to controlling his own destiny in D12 B-Stock tunnel this year. The NS295 is also being put into the hands of a couple other gentlemen that want to pursue the IMPBA B-mod SAW record and Austrailian mod records.

The prototype uses the lawless gas lower, which unfortunately has its share of problems but hopefully those issues can be resolved soon helping to grow the class. I think this introduces the hull enough for now. Questions are welcome. Lets get to the build! I had this kit cut for James Beasley a couple months back, but at the time, I had no time to build it for him. Since my recent unemployment bout, we talked, and next thing I knew the kit was back in my garage. I could not wait to get started.

Here are a couple pics and a video of Buddy Lowes prototype tunnel:

 

[Mike Luszcz]

And now, time to start the build. The first thing you will notice when you get your kit, is everything wood related is included and lots of it! It can be overwhelming, but it should not be. The parts are almost self explanatory, and with the help of this thread, it should guide you threw the build if your plans are building your own!

Parts:

 

[Mike Luszcz]

1

 

[Mike Luszcz]

1

 

[Mike Luszcz]

1

 

[Mike Luszcz]

1

 

[Mike Luszcz]

That concludes the build for this morning. I am heading out to the garage to start chopping up the foam blocks into the correct lengths to fit in between the sponson formers. More soon!

 

[julianconde]

Mike why don't you try to design a gas lower unit ? You have the CAD program and the expertise.

Julian

 

[Mike Luszcz]

1

 

[ww29]

what is price of kit and price of one built

 

[Mike Luszcz]

William, The kit is $235 and includes all the wood parts. The built boat is going to have to hover around $550 I think. It will also include a custom radio box. I am working with James on that right now so I can get it drawn up! Mike

 

[James E Beasley]

Looking good Mike!!! I am actually running the new lower unit from Dominic Young, it is called the "Inigma", an improved design over the X-Ray. Thanks, James Beasley

 

[ww29]

might have to get u to do me one up mike. how is my ps295 coming along

 

[Mike Luszcz]

Will do William. I am working on 6 ps295's while I build this Gas tunnel ,so things are definately getting done! I hope to have you one soon.

OK, got more done on this. Once your outside strip is glued in place, you can then use the hot wire foam cutter to trim the top of the sponson foam like so:

 

[Mike Luszcz]

Next, on the bottom of the sponson, you need to use a bandsaw to cut the correct dihedral in the sponson bottom. You use the bandsaw to cut that foam from the rear of the sponson to about 8" from the front. The reason you stop cutting with the bandsaw at that point, is your dihedral angle will force the blade into the outside strip of wood. That front section will need to be rough cut to remove the bulk, then use a sanding block, or disk sander, and bend in the front foam:

Note: This picture was taken after the block had been cut. The front 8" were rough cut with the bandsaw, then disk sanded to lay out like it should.

 

[Mike Luszcz]

Next you want to take your primary ride pad (the wider one), and use it as a straight edge for hot wiring your non trip foam angle. This takes time to setup, a lot of checking wire to wood distances. Doing this right is critical to the proper non trip angles. The good thing is all those sponson crossmembers serve as really nice lining up patterns to make sure you have the ride pad in the right spot for hot wiring:

You can see where I cut out a couple sections with the cutter to show you how it works:

 

[Mike Luszcz]

Now Bond the non trip to the sponson:

 

[Mike Luszcz]

Next, is the Primary ride pad. This is another critical part of the boat. If this goes on out of wack, you can probably guarantee porpoising, or erratic behavior of the boat. The wood must overlap the inside sponson edge enough that you can sand down to the inside sponson stringer and a nice, sharp edge be left behind on the ride pad. You will notice, I glued some 1/8"x1/8" blocks along that inside sponson ride pad edge. This will give you a true, straight edge down the sponson stringer up to the break point. This also holds that ride pad in place while you tape the ride pad to the sponson. You will also notice those laser etched circles. Those, if you want to use them, will line up with the secondary ride pad that goes on later This will allow you to drill a hole, and put a dowel threw the primary and secondary ride pads, ensuring they are lined up properly. Because I have built so many wood tunnels in the past, I have other techniques for lining them up, so I chose not to use them with my build. The choice is yours! OK, on to the install pics:

I also chose to put an 1/8"x 1/8" block on the trailing edge. This will help lock the ride pad in place while gluing. I glued that to the ride pad, before ride pad installation to the sponson. This kind of locks in, so pay attention when bonding your ride pad!

 

[Mike Luszcz]

Now, you will see in these next pictures, I applied the masking tape a particular way. This s CRITICAL for a nice, flat ride pad. From the rear of the sponson, to the point where it breaks and basically gets higher off the water, I taped from front to back, no overlapping, no doubling. Then, in front of the break, I just started wrapping around the sponson like I normally would on the other pieces. The reason for this, is we need to keep the ride pad tape flat and uniform in this area. What we do after taping that ride pad on both sponsons, we then lay the ride surfaces of each sponson against each other and tape them down. This puts both ride surfaces against each other, flattens them out, and ensures they are right!

 

[Mike Luszcz]

Primary ride pads glued, here they are: