Black Pearl II Hydro - 2020

[longballlumber]

Since I cold not get a nice aluminum (long) sanding block I had to make some out of oak.

you can get a long section of extruded aluminum square from HomeDepot or Lowes. Use a good sanding block to sand the surface flat now you have a long sanding block.

I would agree with Terry on the sanding of the lasered end grain. The laser cutting process seems to "seal" off the end grain of the ply. Without sanding you won't get as good penetration with a glued joint. A good glue joint creates a mechanical bond between the two substrates and your glue. That's why G10 has a tendency to delaminate at the glue joint. The glue can't penetrate into a fully cured substrate (g10). Just my $.02, mileage may vary.

[ray schrauwen]

Sounds good Mike. I opted for some 3-1/2" wide oak that I can staple roll sand paper to. I do use a 1/2" wide strip of 2 sided tape down the middle to keep it flat when I wrap the ends and staple the paper down. It's getting very difficult and or expensive to go the adhesive backed sand paper up here. Great planes is out of the game a Dubro isn't as good it looks like.

I have a pair of sanding blocks now, 60 grit and 150.

Now to setup the build board now that I'm squared away proper.

[Shooter]

Unfortunately, I'm finding that more and more hobby shops are not carrying building supplies. Seems everyone wants RTW. Same with the airplane market. I glued the bottom last night. Gives me a nice excuse to showcase my collection of weights again.

[Greg Schweers]

That looks like overkill on the weights 50 pounds plus

[ray schrauwen]

Now I know what burn marks on the surface you mean Pete. I just pulled parts out of the box, the to face is beautiful while the bottom has what you describe. Sanding today and mock up.

50lbs does sound extreme doesn't it? lol... if it works.

[eric113]

To keep the bottom flat, 50lbs doesn’t sound like alot.

[T.S.Davis]

That's why G10 has a tendency to delaminate at the glue joint. The glue can't penetrate into a fully cured substrate (g10).

Super accurate. This is what happened to Ty's last P sport. Lasted two + seasons but eventually the belly fell out of it. There were other factors but mostly I think it was joint failure.

For those thinking about using G10, you have to be really careful where you use it. It's tough as nails but if you are bending it much to conform to a shape it puts constant strain on the joint. You have to scuff with 80 grit and clean with 99% alcohol or acetone. Even then it's a crap shoot. Worthy trade? Meh. Depends on how good you are at fixing crap I guess. I've skinned entire boats with G10. Makes for a really stiff boat but a really heavy boat. Can't predict it's life span. Lately just my shoes are G10. Little bend so the joints aren't under too much stress but can take a hit without damage. I can also see through the G10 to know if I missed any mating surfaces when I bond them to the frames. Working so far but it's still a mechanical joint so time will tell.

I'm sure we've all had this conversation before but for those that haven't. I think of my wood joints like this (OH sure now)...... If you glue two steel pieces like say 1-2-3 blocks together with epoxy you could probably break them apart with a few good taps from a screw driver handle. Cured epoxy is just a glorified plastic. Adhere it to a solid nonporous surface and it's hanging on fer dear life. Now imagine you epoxied two sponges together. Let the soak into each sponge a bit. Now let that cure. You might rip the sponge but that joint is forever. Same with the wood. The more the epoxy penetrates into the grain of the wood the more ONE single thing the two pieces become. If the wood grain is all sealed up with burn marks it can't penetrate. It's a judgment call on every kit if you need to clean the slots. Might take an extra half hour to fiddle fart around with them. Worthy trade? For me it is.

This is another reason to avoid a 5 minute epoxy like Loctite or something. It will hold for as bit but the epoxy cures before it can soak into any of the wood fibers. No matrix is formed. No "forever" joint. And yes I've used Loctite epoxy to build entire boats. Worked fine......until it didn't. "Until it didn't" could have been many more heats with an epoxy better suited to the job.

[T.S.Davis]

That looks like overkill on the weights 50 pounds plus

I use about 15 pounds myself. I end up with about 20 when I do the deck but I'm trying to cover as much space as I can. I hate decking boats. Sucks every time.

[ray schrauwen]

Yes it does.

[eric113]

I use about 15 pounds myself. I end up with about 20 when I do the deck but I'm trying to cover as much space as I can. I hate decking boats. Sucks every time.

It does suck. I’m still trying to learn how to glue skins down.

[Shooter]

I like the sponge analogy! I sanded the edges off the bottom sheet last night. It's not going to be as mean looking as Terry's, but it's the nice guys you need to watch out for! I remember Pag's daughter looking at one of my boats that had a super nice paint job and saying how pretty it was. Mike tells her "The pretty ones don't go fast, honey".

[lohring]

The bible on building wood boats with epoxies is The Gougeon Brothers on Boat Construction. I have a first edition signed by the late Mead Gougeon. Read chapter 9 on bonding.. My late father in law had a trimaran built by the Gougeons that looked like it was fiberglass. It sailed across the great lakes, down the Mississippi, around the gulf and up the east coast. He and his wife lived on it for years. It may still be around.

Lohring Miller

[T.S.Davis]

It does suck. I?m still trying to learn how to glue skins down.

This wont make them perfect either but the last few I did like this. Notice the curved blocks. I use the frames to trace the shape on to the blocks and then cut them out on the band saw. Some sanding and filing to clean them up. Not perfect but pretty close to the shape. You still have to weight the flat parts and search for gaps. Wiggle, wedge, add something here or there to make sure it;s all down and as tight as you can get it. Center section is clamped with a piece of wood and wax paper in between the boat and the block just in case. I've adhered blocks there before. Really really sucks.

Down side is....... that's a $150 worth of bar clamps. One winter I built 5 different wood boats in about 3 months. Some simultaneously. The clamps pile up if your insane.

V10.8 - deck.jpg

Great post Lohring. I got some read'n to do.

[lohring]

Thanks. I've used their methods on full size boats in the distant past. All our epoxy/glass Leecraft tunnels were built with West ProSet epoxy. Not inexpensive, but worth it.

Lohrong Miller

[ray schrauwen]

This wont make them perfect either but the last few I did like this. Notice the curved blocks. I use the frames to trace the shape on to the blocks and then cut them out on the band saw. Some sanding and filing to clean them up. Not perfect but pretty close to the shape. You still have to weight the flat parts and search for gaps. Wiggle, wedge, add something here or there to make sure it;s all down and as tight as you can get it. Center section is clamped with a piece of wood and wax paper in between the boat and the block just in case. I've adhered blocks there before. Really really sucks.

Down side is....... that's a $150 worth of bar clamps. One winter I built 5 different wood boats in about 3 months. Some simultaneously. The clamps pile up if your insane.

V10.8 - deck.jpg

Great post Lohring. I got some read'n to do.

Nice! I like those blocks but no time to make those now. And yes some reading to do. Thanks Lohrong !

[ray schrauwen]

I've got all the faces sanded now. Now comes the dirty little slots. I think I'll try doing those while watching a movie later on. The glue in the picture is not necessarily what I'm going to use to build the boat since it's a lot thicker than I anticipated it would be. It's designed for hardwood gluing applications and for making wood airplane parts real airplanes not toys. I also have some West systems here and slow and medium speed hardener it looks like I'm going to go for the West systems to do most of this boat. I still have to get some of that reading done I'm sure there's lots of important stuff in there.

Now I know how not to take a picture on my cellphone, lol.

[longballlumber]

Here you go..

There is no reason you can?t use the Systems Three T-88 epoxy. From what I read quickly it?s effectively 60mm epoxy. It will take overnight to fully cure. Much like the WestSystems you have. I would say the biggest difference between the two would be the viscosity and the gel times. The thinner WestSystems is going to penetrate better IMO. I don?t know that either help you build faster.

[ray schrauwen]

Cool. I'm going to use it where fillets are needed and gap filling. My grid paper I tested to see if glue sticks was a fail. I need to cover that surface with parchment.

[TRUCKPULL]

Drive Angle

I have a question for Sport Hydro builders.
On my Black Pearl.
I have found that with the speed we are achieving with the rudder and turn fin set straight in line, that you have to adjust the strut to get the boat to run in a straight line. With the strut straight the boat wants to turn into the course.

As of right now I am using a 1.5 degree wedge between the transom and the strut mount.

Seeing that 1 degree is .210" per foot.
From the rear of the strut to the back edge of the ride pads is 18.5 inches.
So my drive force is at 31/64 inches off center. (or 1/2 off center)
at the rear of the sponsons.

If I was to move my strut sideways off center to mount it square to the transom.
How much would I have to move it?

Larry

[Shooter]

Gee Larry, that's a good question. I'm with you at 31/64". 18.5*tan1.5 = 0.48 = 31/64". Question is if that is the number you need to offset.

[TRUCKPULL]

Gee Larry, that's a good question. I'm with you at 31/64". 18.5*tan1.5 = 0.48 = 31/64". Question is if that is the number you need to offset.

I am thinking that the angled thrust is a lesser forward force then 90 degrees is?

I was also hoping some of the Rigger SAW guys may answer this.

Larry

[Shooter]

Yes, the saw guys should know. I think in both cases you are losing some FWD thrust because it is creating a moment about the CG causing the boat to want to rotate. Propwalk does this as well.

[TRUCKPULL]

Yes, the saw guys should know. I think in both cases you are losing some FWD thrust because it is creating a moment about the CG causing the boat to want to rotate. Propwalk does this as well.

Pete
I am using an ABC 1815. Less lift, and walk, but the same dia. and pitch as your H5 prop.

Here are two pictures of the carbon fiber wedges that I make.
These were made from 1/16" plate, a little thin,
I will be making new ones from 2mm carbon fiber plate.
If anyone is interested, PM me.

Larry

[Shooter]

Started the sponsons last night.

[eric113]

Raced this past Saturday, my boat found the bottom of 8? waters. Also had a club member slice into left sponson.

[T.S.Davis]

Started the sponsons last night.

I must have a 100 of those little clamps. Pete, do you ever us a piece of flat stock of some sort and clamp that with the skin so that the surface comes out straight.....er? I do that with the shoes. Get me closer to straight....ish. Not sure why I never did it on that outer skin.

[TRUCKPULL]

Terry
Do you mean like this?


Larry

[ray schrauwen]

Am I to assume I need to buy a nose block from the hardware store since I did not see any in the box? What size?

[RandyatBBY]

Hi I started this boat early last summer when the bottom of my PLTD Sport lost the full center sheeting. I got this boat and quickly realized I did not have the time to build. After the NAMBA Nationals in October it was my goal to build this boat this winter along with three others. 2 scales and a Q Sport, this is how it looked to start
IMG-3276 (1).jpg
skin on bottom
IMG-3352.jpg
first skin on deckI use masking tape to hold while epoxy dries. I also put milled FG and caboseal to make a peanut butter consistancy to increase strenght in bond and rigidity.
IMG-3354.jpg
I changed the front of the sponsonson the bottom a little. and I am going to use a BBY cowl from the Zephyer on a plywood more later.
Attachment 176146
Sense I am retired I am enjoying building and running other peopls hulls.

[ray schrauwen]

Randy it looks like you screwed the transom down to the build board.