Coring and Lamination for a 17ft picklefork outboard

[JRider]

Looking for suggestions on lamination/material/schedule and coring thickness (and material) for a 17ft picklefork outboard. I am thinking going full polyester for the first one as it will be a test boat. Team Hawaiian built a few of these in about 1998, not sure how the mold ended up in Wisconsin but that is where I picked it up and it is in MI now.

Plan would be going 15" shaft on a bracket.

I have an STV Euro and a Hydrostream HST that I will be copying some of the structure from.

 

[138]

How much hp? How much offset?

 

[JRider]

How much hp? How much offset?

http://www.mercuryracing.com/outboards/engines/optimax-200xs-ros/

You mean setback? There is no built in setback in the hull so 6 or 8 inches to start...no really telling how much until its tried, not sure how this hull will react to outboard power. Going to have to test it. Have been into outboards for over 25 yrs, dont think that is a big issue at all.

 

[AzGeo]

That boat looks like one I went to 're-design' for Bruce King back in the early 90's .

The tunnel areas are not parallel, the riding surfaces are also not parallel, correct ?

PLEASE, let's look over and discuss many more photos, especially of the bottom, before you spend any money on this project .

It may run (not well) as a jet, but be undrivable with an I/O or outboard .

"Measure twice, spend once" .

 

[Gelcoater]

JRider,you would be wise to listen to AzGeo here.

Post as many pics from as many angles as possible.

 

[JRider]

 

[JRider]

Ill try to get some mold pics up. It does have 2 small steps in the sponsons and one in the pod.

 

[JRider]

 

[AzGeo]

So, are the 'riding surfaces parallel', from bow to transom ? Do the 'tunnels' taper IN going back to the transom ? If the bottom is still trying to 'pinch the water in' going to the transom, it will be very hard to control with an O/B at speed .

More photos of the inside of the mold, or the bottom of the boat, please .........

 

[JRider]

May have more on my hard drive at home. Mold is covered up really well so hard to get access. I can go under it and measure...are you talking inside sponson to inside sponson measurements front and rear?

I will have to look at it when I get home from work.

 

[JRider]

Inside sponson to sponson measuring the bottom of the mold it does not pinch in. However the center pod does not run parallel to the bottom of the sponsons. Center pod has a step in it so I'm not sure how it even worked with a jet...

 

[AzGeo]

This may have been up dated after I looked at it .

Just remember, when the boat 'gets up on top', the riding and lower air trap edges must not 'attack' each other . Reducing the volume of air is how a tunnel works, but trying to 'control water flow' under the riding surfaces just does not work .

I remember the outer sponsons 'going closer together' as they went to the transom . You may have a 'revision' of the old design that I inspected .

MEASURE everything, make sure the riding surfaces (all the wet hull bottom areas) are parallel, this would be completely different from the design I was asked to 'improve' .

Mr King didn't want to spend the money trying to correct what was wrong with the original design .....

Good luck !

 

[JRider]

This may have been up dated after I looked at it .

Just remember, when the boat 'gets up on top', the riding and lower air trap edges must not 'attack' each other . Reducing the volume of air is how a tunnel works, but trying to 'control water flow' under the riding surfaces just does not work .

I remember the outer sponsons 'going closer together' as they went to the transom . You may have a 'revision' of the old design that I inspected .

MEASURE everything, make sure the riding surfaces (all the wet hull bottom areas) are parallel, this would be completely different from the design I was asked to 'improve' .

Mr King didn't want to spend the money trying to correct what was wrong with the original design .....

Good luck !

yeah, really do not see how pinching the sponsons could ever possibly make a boat run better/faster. I will have to look at the center pod as far as being on the same plane as the sponsons. I can tell you that all the mold edges/corners are very sharp. My HST and STV hulls will be a good reference as far as running surface...the HST has a step in the the center pod similar to the mold.

 

[Gelcoater]

When are you going to start this build?

 

[JRider]

Just finishing up my STV for the year. Fixed/regeled transom and regeled beach rash then rebuilt/painted trailer whole trailer while boat was upside down. Trying to figure out ventilation and stable heat for my garage so I dont run into gel issues as the weather gets colder. Ah, beautiful Michigan.

I was hoping to get a some recommendations here on how many layers of glass, what kind of glass and how thick of coring to go with. I have a full roll of 1708, small roll of 1700, and a roll of roven. Going to need a drum of Poly. Need a little more defined materials list and get to ordering.

I see a lot of the new build threads use balsa coring...why? I would think foam coring would be the way to go but I am no expert. I have used balsa before I just see what happens to it when it is not totally encapsulated or with a crack and water intrusion.

 

[Gelcoater]

Just finishing up my STV for the year. Fixed/regeled transom and regeled beach rash then rebuilt/painted trailer whole trailer while boat was upside down. Trying to figure out ventilation and stable heat for my garage so I dont run into gel issues as the weather gets colder. Ah, beautiful Michigan.

I was hoping to get a some recommendations here on how many layers of glass, what kind of glass and how thick of coring to go with. I have a full roll of 1708, small roll of 1700, and a roll of roven. Going to need a drum of Poly. Need a little more defined materials list and get to ordering.

I see a lot of the new build threads use balsa coring...why? I would think foam coring would be the way to go but I am no expert. I have used balsa before I just see what happens to it when it is not totally encapsulated or with a crack and water intrusion.

i sure hope your garage is detached!
You're going to need a kick ass central heating system.You could use a propane heater but the risk of fire is self explanatory and just adds to the air quality issues.
I can give you advise on gel,but as far as lamination schedules I can't say much.

 

[Backlash]

I think the coring material used by different builders/hobbyists is purely based on preference. Yes, some coring materials have greater strengths and qualities than others; I'm not going to argue that.

As far as using balsa as a coring material, I think a lot of the "West Coast" guys prefer the look of the balsa coring when it's done correctly. It is borderline sexy (Just look at Plaster Dave's Schiada!).

Foams are used by many builders too (Sail and power), but they too have problems. I guess it all depends on what the ultimate goal of "The" part was (Transom, stringers, deck, etc.)

Hotboat magazine said it best years ago during an evaluation and a write-up for a Schiada boat.... "When wood is done like this, wood's all good."

 

[Gelcoater]

I think the coring material used by different builders/hobbyists is purely based on preference. Yes, some coring materials have greater strengths and qualities than others; I'm not going to argue that.

As far as using balsa as a coring material, I think a lot of the "West Coast" guys prefer the look of the balsa coring when it's done correctly. It is borderline sexy (Just look at Plaster Dave's Schiada!).

Foams are used by many builders too (Sail and power), but they too have problems. I guess it all depends on what the ultimate goal of "The" part was (Transom, stringers, deck, etc.)

Hotboat magazine said it best years ago during an evaluation and a write-up for a Schiada boat.... "When wood is done like this, wood's all good."

Border line sexy?
When I look at some of the old Schiadas,Coles,or anything Harlin built,the mahogany,ash,birch,etc all flow coated and wet looking...it gives me a chubby.

 

[Backlash]

Amen Brother!!!

 

[JRider]

Going to go 2 layers 1708, 1/2 inch balsa core, and 2 more layers 1708. I can get VE cheap enough now that I might just go with it.

 

[Gelcoater]

Going to go 2 layers 1708, 1/2 inch balsa core, and 2 more layers 1708. I can get VE cheap enough now that I might just go with it.

Here's a thread that might interest you.


http://www.riverdavesplace.com/forums/showthread.php?1029-Fiberglass-Construction-101

 

[AzGeo]

the 1708 you want to use ? I may be 'old school', but to prevent 'print thru', I've always used "two layers of 2oz mat" against the gel . Then go with Strength and Body materials . If you are talking about a regular 1708 with 1/2oz or 1oz of mat on it, I think the boat will end up looking like a golf ball .

Am I missing a new product here ?

 

[Backlash]

If I remember correctly, the 1708 is 17 ounces biaxial with 3/4 ounce chopped strand mat. I think.

 

[JRider]

Here's a thread that might interest you.


http://www.riverdavesplace.com/forums/showthread.php?1029-Fiberglass-Construction-101

Yup already read it...did learn a few things there. Thanks.

 

[JRider]

the 1708 you want to use ? I may be 'old school', but to prevent 'print thru', I've always used "two layers of 2oz mat" against the gel . Then go with Strength and Body materials . If you are talking about a regular 1708 with 1/2oz or 1oz of mat on it, I think the boat will end up looking like a golf ball .

Am I missing a new product here ?

1708 is 17 ounces biaxial with 3/4 ounce CSM.

How much CSM does it really take to prevent print through? Maybe I should make a test panel?

 

[Backlash]

Did you make a test panel Jrider? If so, what did you discover?

 

[AzGeo]

2 layers of 2 oz mat, on the gel in one layup . Then go to a 4 oz cloth or a light 1708 with at least 3/4 oz of mat on it .

Unless your molds have no 'tight corners', or 'sharp edges', you will need something LIGHT to stay wet and stay in the tight places, after being 'rolled out with metal rollers' .

You try to go in first with 'heavy or woven fibers', and you will not only have 'print thru', but you will have a bunch of 'voids and air bubbles under the gel, into the lamination'.

We have all seen hulls with 'holes' in the edges of the strakes and chines . The gel was stuck to the mold, but the lamination never went all the way down into the corners ......

 

[OFFSHORE GINGER]

4 oz for your skin coat will be just fine .

 

[Gelcoater]

4 oz for your skin coat will be just fine .

I'm sorry.
Did you say something?

 

[OFFSHORE GINGER]

Beg your pardon ..............................

 

[JRider]

Winter is rolling in quick, got a lot of shit to take care of before snow flies so no work on the boat yet.