SWISS CHEESE TUB

[dwilfong]

I have bin thinking again

Starting a new build and trying to make a lighter boat. When I remembered the old Pontiac Super Duty cars of the early 1960 and there swiss cheese frames.

Has any one tried to drill holes in the tub to make it lighter. Then use finish epoxy to put carbon fiber on the out side. It seems like an easy way to reduce the weight.

Any thoughts on this.

David

 

[PAUL STIRTON]

I have bin thinking again

Starting a new build and trying to make a lighter boat. When I remembered the old Pontiac Super Duty cars of the early 1960 and there swiss cheese frames.

Has any one tried to drill holes in the tub to make it lighter. Then use finish epoxy to put carbon fiber on the out side. It seems like an easy way to reduce the weight.

Any thoughts on this.

David

I did this to a 90 jaguar from tide water many years ago and while it reduced weight, the first turn bouy it got near was the end of the tub. As you said laminating with Carbon Fibre may work. I used 1mm Aircraft Ply when I did mine. Iwpould also leave plenty of meat around the motor mount area.

 

[dwilfong]

I have bin thinking again

Starting a new build and trying to make a lighter boat. When I remembered the old Pontiac Super Duty cars of the early 1960 and there swiss cheese frames.

Has any one tried to drill holes in the tub to make it lighter. Then use finish epoxy to put carbon fiber on the out side. It seems like an easy way to reduce the weight.

Any thoughts on this.

David

I did this to a 90 jaguar from tide water many years ago and while it reduced weight, the first turn bouy it got near was the end of the tub. As you said laminating with Carbon Fibre may work. I used 1mm Aircraft Ply when I did mine. Iwpould also leave plenty of meat around the motor mount area.

I don't think I will put holes in the eng mount area. Have a set of tub sides that came out short after sanding. Will start drilling on them and check the weight loss as I drill.

I think small holes and lots of them might be the trick. Spacing and size will be the thing I need to decide on.

David

 

[camaroboy383]

to me,,, to an extent you are defeating the purpose... you are drilling holes to make the hull lighter,,, yet you are adding the wieght of the epoxy and the carbon fiber back on... so how much will you really lose when all is said and done sealed and clear coated??? just somthin to think about...

ac

 

[misshydro]

to me,,, to an extent you are defeating the purpose... you are drilling holes to make the hull lighter,,, yet you are adding the wieght of the epoxy and the carbon fiber back on... so how much will you really lose when all is said and done sealed and clear coated??? just somthin to think about...

ac

I agree too..

 

[Paul Traufler]

Well the holes are weight, as long as the "stuff" you put in place of the holes is lighter then you will get a weight loss. However at the same time the weight difference may not be that much, couple that with all the labor to do this and you may as well start over and use carbon fiber materials for the get go. Remember the reason for the new materials is to reduce weight AND be stronger also. If the material is twice as strong you can use half as much of it. (This is not 100% true but something to shoot for.) Just my 2 cents worth...

to me,,, to an extent you are defeating the purpose... you are drilling holes to make the hull lighter,,, yet you are adding the wieght of the epoxy and the carbon fiber back on... so how much will you really lose when all is said and done sealed and clear coated??? just somthin to think about...

ac

I agree too..

 

[camaroboy383]

i would put money on it that the wieght loss wouldnt be significant with the method above... now if you just use lighter thinner wood,,,there ya go.... or like stated above,,,start with thin carbon and just dont stop till its done... i would phisically love to see the wieght of the lost wood,,,, then i would love to see the wieght of the epoxy,,,clear coat,,and carbon fiber apposed to the wieght of the wood.... bet you dont lose much if any,,,,crap,,, if you epoxy the heck out of it i bet you would exceed the wieght of the wood lost....go for it,,,,wiegh it all and post the results.... just do one tub side and leave the other stock,,,no holes,,no carbon,,,then wiegh both and see what you get...

 

[TUNLBOTR]

David,

Talk to Marty, they have been working on a neat way to do it. Look at ACP composites carbon veneer, can epoxy over klegecell for a beautiful finish....

RP

 

[dwilfong]

David,

Talk to Marty, they have been working on a neat way to do it. Look at ACP composites carbon veneer, can epoxy over klegecell for a beautiful finish....

RP

I saw Marty's 45 boat at the Dover race at the end of last year. It is very very nice boat! Can't weight to See it run.

The composite is very nice but very expensive. Dragon plate makes some Divincell core .25" thick material but the stuff is very pricey.

Using the 1/4" ply and using the finish epoxy you should get a very good bond. I already use the finish epoxy so the only extra weight would be the carbon fiber. Witch will be far less than the wood. the tub sides weigh .54 of a pound right now. Building a 3lbs. 21 rigger that is allot of the weight.

It all adds up a gram hear and there is all it takes. Also it will help with the tail weight if holes are placed right.

I am going to try it on the tub sides I messed up and see what happens. As far as the labor it's free and fun at that.

David

 

[Hydro Junkie]

Please tell me that 1/4" is a typo or only for engine doublers

 

[dwilfong]

Please tell me that 1/4" is a typo or only for engine doublers

No 1/4" tub sides.

 

[dwilfong]

Well this is what I got. 30g less with the holes.

 

[mtruex]

Please tell me that 1/4" is a typo or only for engine doublers

No 1/4" tub sides.

why 1/4 inch sides?

 

[Marty Davis]

Well this is what I got. 30g less with the holes.

David:

When you add up all the extra epoxy you will need, you will find that it weighs more. Just get some 1/8" or even 1/4" Klegicel and use that. It is very strong and super light.

 

[dwilfong]

The plans call for 1/4" tub sides. How thin can you go on the tub sides.

The last build I used 5mm luan panels. But it did not hold the dimensions got a twist and bend in the in the tub.

Trying to keep the cost down. Ply wood is cheep and my time is free.

Would like to try Klegecell or Divincell. The problem is getting it in small quantity. This is a hobby don't what to break the bank. Hate to cry poor mouth but thats the reality of it.

David

 

[misshydro]

The plans call for 1/4" tub sides. How thin can you go on the tub sides.

The last build I used 5mm luan panels. But it did not hold the dimensions got a twist and bend in the in the tub.

Trying to keep the cost down. Ply wood is cheep and my time is free.

Would like to try Klegecell or Divincell. The problem is getting it in small quantity. This is a hobby don't what to break the bank. Hate to cry poor mouth but thats the reality of it.

David

what size is this rigger? think you can use 1/8 as sides to that tube.. up the .67? Just epoxy the sides on good.. should hold up every well... Man 1/4 ply that to much! maybe1/4 for the transom and bulkheads?

 

[Paul Traufler]

1/4" for a 21 rigger is pretty big stuff! Oh and Luan is not a very good "ply wood" it is mostly filler. Look for 5 ply 1/8" ply, that is the good stuff. CF = $ no way around that one, sorry!

 

[Terry Keeley]

I did a SAW boat a few years ago with 1/4" Rhoacell and a layer of 6oz & 3oz CF per side, it's taken a couple hard tumbles and it's still good.

Very light...

http://gallery.intlw...s.php?album=707

ps: 6oz CF isn't that pricey, 1 yd x 50" wide is only about $40. You don't need to bag it either, if you're careful with your resin and clamp or press it together well you'll get the same results.

Trust me, you can't beat carbon for strength : weight.

 

[dwilfong]

I did a SAW boat a few years ago with 1/4" Rhoacell and a layer of 6oz & 3oz CF per side, it's taken a couple hard tumbles and it's still good.

Very light...

http://gallery.intlw...s.php?album=707

ps: 6oz CF isn't that pricey, 1 yd x 50" wide is only about $40. You don't need to bag it either, if you're careful with your resin and clamp or press it together well you'll get the same results.

Trust me, you can't beat carbon for strength : weight.

I see that CST has it in small sizes. What grade is best.

This looks like what I was looking for.

David

 

[Terry Keeley]

I did a SAW boat a few years ago with 1/4" Rhoacell and a layer of 6oz & 3oz CF per side, it's taken a couple hard tumbles and it's still good.

Very light...

http://gallery.intlw...s.php?album=707

ps: 6oz CF isn't that pricey, 1 yd x 50" wide is only about $40. You don't need to bag it either, if you're careful with your resin and clamp or press it together well you'll get the same results.

Trust me, you can't beat carbon for strength : weight.

I see that CST has it in small sizes. What grade is best.

This looks like what I was looking for.

David

I used the 4.7 lb. stuff:

http://www.cstsales.com/Rohacell_71_IG.html

Trust me, once you go carbon, you'll never go back!