42" Tunnel Hull Buildup- NOW FINISHED!!!! NEW PICS!

[Mike Luszcz]

Well, having a 48" DPI 1/4 Scale Tunnel w/ an 11cc K&B OB and enjoying the large scale boats, I wanted to build one from scratch. I took some JD Dunlap 27 plans and modified them to build a 42" tunnel hull for my 11cc. I already make a mold for a cowling and will be popping out a part from it soon. Here is the tunnel build so far...Enjoy!

 

[winzracing]

Hey my 48 DPI is great and runs perfect.I must say it did take some time to get it set up right but i think they run great and handle pretty well.What was your setup? what prop , what height trim etc.Baz

 

[Mike Luszcz]

Its an 11cc K&B, Silver bullet pipe and header, cavitation plate, and somewhere around 1/2 lb of lead up front..I would have to count it to be exact. I have it staying on the water now, and its fast, but it took a lot to get it there! Any pics of yours? I would love to see them! Mike

 

[Jerry Dunlap]

Your wood boat looks like a scaled up JD 27 Tunnel.

JD

 

[Mike Luszcz]

Your wood boat looks like a scaled up JD 27 Tunnel.
JD

Jerry, That would be correct! I bought the JD 27 plans a few months back to build a 27" hull...which is put on hold right now, but since I am new to building (this is my first boat and not about to attempt a WOF) I wanted a template to start from and I needed a 42" boat so these plans were a good start. I did have to redraw all of the bracing cut-outs on CADD, and redo how the sponsons were made. I am guessing on your original plans the right sponson was designed to be shaped different than the left sponson? On each crossbrace the sponsons were shaped totally different right vs. left. All I could figure was it was setup for oval racing? I don't race so I needed them the same. I got the cowling part layed up last night, so I should have some pics of it soon. I think I am going to do a 48-52" hull next...for a zenoah outboard!

 

[Mike Luszcz]

Well, Things are looking up, at least to me. I was able to get the cowling out of the mold..barely!!, but its easy to fix, so no worries, here are the pics!

I think its gonna be a pretty hot boat! I cannot wait to get it done now. Getting a cowling created I knew would be the toughest challenge..so Im pretty happy! Mike

 

[Jerry Dunlap]

Really looking good. BTW, the sponson angles were supposed to be the same.

JD

 

[Kris Flynn]

Looks good, and trust me the more you build, the less bog you will need to smooth them out.

Next time maybe try: more stringers for support; thicker ply to stop sagging; and careful sanding.

All the best and the cowl looks good too!

Kris

 

[Mike Luszcz]

Looks good, and trust me the more you build, the less bog you will need to smooth them out. Next time maybe try: more stringers for support; thicker ply to stop sagging; and careful sanding.

All the best and the cowl looks good too!

Kris

Thanks for the comments everyone. This is my first boat from the ground up and believe me, there will be more! I am already wanting plans for JD's kneeler. My biggest problem right now, is proper tools for cutting all these parts..I just cannot swing the high end tools that really make things nice. Luckly the epoxy (MAS) that I am using is extremely thin, and of course the micro balloons don't weight anything, so the boat is still very very light...compared to the 48" DPI I have. I have painted many cars so I look forward to the painting part of this build..things should shape up then! Thanks and any more advise you guys have, I will soak it in. Take care, Mike

 

[Mark Poole ModVP]

Mike, looks like the cowl stuck to the mold some. If I can help, what did you use for mold release? And, is that white gel coat on the cowl? Did the mold shine up really slick before you applied mold release?

 

[Mike Luszcz]

Mike, looks like the cowl stuck to the mold some. If I can help, what did you use for mold release? And, is that white gel coat on the cowl? Did the mold shine up really slick before you applied mold release?

Hey, Yeah, it stuck I used mold release on it, but those spots apparently stuck, and caused what you see. I waxed it up 4 times before applying the gel coat (yep, the white is gel coat). Maybe I need to try that PVA stuff? I have never done a mold before! lol, so I was not sure what to expect. Your help is graciously welcomed! thanks, Mike

 

[MarkScott]

When you get ready to work on the 48-52" tunnel, let me know. I've got JD's 47" Solution on pdf file that can be sent to ya.

Nice build btw....

 

[Mike Luszcz]

When you get ready to work on the 48-52" tunnel, let me know. I've got JD's 47" Solution on pdf file that can be sent to ya.
Nice build btw....

That would be awesome. I am not sure what that boat looks like, my email is [email protected], I would love to see the plans! Thanks everyone! Mike

 

[MarkScott]

That would be awesome. I am not sure what that boat looks like, my email is [email protected], I would love to see the plans! Thanks everyone! Mike

Plans sent.

 

[Bill Britton]

Mike, looks like the cowl stuck to the mold some. If I can help, what did you use for mold release? And, is that white gel coat on the cowl? Did the mold shine up really slick before you applied mold release?

Hey, Yeah, it stuck I used mold release on it, but those spots apparently stuck, and caused what you see. I waxed it up 4 times before applying the gel coat (yep, the white is gel coat). Maybe I need to try that PVA stuff? I have never done a mold before! lol, so I was not sure what to expect. Your help is graciously welcomed! thanks, Mike

Use Honey Wax for waxing your molds.

This is the only mold release wax that Egg Harbor Yachts allows in their shops so it's good enough for me!

TR's Hi-temp mold release wax is made for big jobs and therefore will not get hot enough at curetime to properly do the job. I wax my virgin molds at least 10-12 times before first use. then 3-4 times after each part for the first 5 parts. After that you can wax about every 20 pulls. I prefer not to use PVA as you will have to go back and re-polish your part after pulling.

 

[Mike Luszcz]

Mike, looks like the cowl stuck to the mold some. If I can help, what did you use for mold release? And, is that white gel coat on the cowl? Did the mold shine up really slick before you applied mold release?

Hey, Yeah, it stuck I used mold release on it, but those spots apparently stuck, and caused what you see. I waxed it up 4 times before applying the gel coat (yep, the white is gel coat). Maybe I need to try that PVA stuff? I have never done a mold before! lol, so I was not sure what to expect. Your help is graciously welcomed! thanks, Mike

Use Honey Wax for waxing your molds.

This is the only mold release wax that Egg Harbor Yachts allows in their shops so it's good enough for me!

TR's Hi-temp mold release wax is made for big jobs and therefore will not get hot enough at curetime to properly do the job. I wax my virgin molds at least 10-12 times before first use. then 3-4 times after each part for the first 5 parts. After that you can wax about every 20 pulls. I prefer not to use PVA as you will have to go back and re-polish your part after pulling.

OB Nut, Thanks so much for the plans..That will definately be happening in the future! Thanks Bill for the mold release info. I have some serious work to do to my mold now to remove what got stuck, and smooth it back out. Its not a perfect mold anyways, but once the part is pulled, its easy to "finish" the piece out. It was never ment for production anyways, just a few here and there...but I do hope future parts will come out in one piece!

I got the bottom of the left sponson finished today, and got the cowl fixed as well. New pics sooner than later! Take care, Mike

 

[Bill Britton]

Mike, looks like the cowl stuck to the mold some. If I can help, what did you use for mold release? And, is that white gel coat on the cowl? Did the mold shine up really slick before you applied mold release?

Hey, Yeah, it stuck I used mold release on it, but those spots apparently stuck, and caused what you see. I waxed it up 4 times before applying the gel coat (yep, the white is gel coat). Maybe I need to try that PVA stuff? I have never done a mold before! lol, so I was not sure what to expect. Your help is graciously welcomed! thanks, Mike

Use Honey Wax for waxing your molds.

This is the only mold release wax that Egg Harbor Yachts allows in their shops so it's good enough for me!

TR's Hi-temp mold release wax is made for big jobs and therefore will not get hot enough at curetime to properly do the job. I wax my virgin molds at least 10-12 times before first use. then 3-4 times after each part for the first 5 parts. After that you can wax about every 20 pulls. I prefer not to use PVA as you will have to go back and re-polish your part after pulling.

OB Nut, Thanks so much for the plans..That will definately be happening in the future! Thanks Bill for the mold release info. I have some serious work to do to my mold now to remove what got stuck, and smooth it back out. Its not a perfect mold anyways, but once the part is pulled, its easy to "finish" the piece out. It was never ment for production anyways, just a few here and there...but I do hope future parts will come out in one piece!

I got the bottom of the left sponson finished today, and got the cowl fixed as well. New pics sooner than later! Take care, Mike

A tip for getting the stuck gelcoat out of the mold is to use the edge of a spoon. use the edge and try to catch the edge of the gelcoat. It will pop out in small pieces and not damage the mold. (ask me how I know!)

 

[Mike Luszcz]

Haha, Thanks for the info, I will give that a try later today!

 

[Mike Luszcz]

I have the hull done finally! Building the radio box now. The boat is all epoxyed, and cowl is fitted! I will have pics hopefully tonight. Pretty excited over here! Mike

 

[topfuel443]

Looking good Mike, now lets see some finished product pictures!

~James