How to make vac bagged composite stringers

I’ve done this a couple of times and it has turned out well.  I don’t use stringers much anymore but I am building a couple of longer boards and need stringers, so here goes. 

Details:  I used two sheets of sort of thick (1/20 inch?) mahogany veneer from “Certainly Wood” about 10 ft by 20 inches sandwiching a sheet of balsa that was 1/8 inch thick.   By the cheapest mahogany you can find.  All you will see is the edge.  I had the balsa sheet from a balsa veneer project (Bert Burger style) that I didn’t finish.  I had glued it up with super glue and was searching for a use.  I used Resin Research slow resin.  I recommend the little roller rather than a squeegee.  It puts out an even coat and does it quick.  My mahogany veneer was a little warped and I gave the bagging a little help with some weights.  Last time I did this I taped it down to the garage floor…  Do not make that mistake.  I made it for you.  Price paid.  Do as I say.

The comp

I’ll post up the pictures from my phone in a follow up post.  I’ve found that really easy to do.  

Cool. Thanks for sharing. Im interested in pics when you get them.

the iphone thing didn’t work as well as I remembered.  now I’m cranky.  here are the pics another way.

 




more.

and a picture of the stringer from the last time I did this.


Cool…Thanks GT.

 

This is way better than the apology threads, or the “what- are- you” currently riding thread, or those I’ll post 15,000 questions and now I’m an expert guy.

I see you are using  full sheet, do you get many air bubbles in the lay up? Have you tried the same process but used contact cement and a roller?

 

RH

 

 Fish pump vacuum rig !!   You know I love that.  

RH, I won’t  read let alone respond to those posts anymore.  Spot on about the 15,000 questions and suddenly an expert. Be enthusiastic, be humble, be generous, be reserved and be complimentary or shut up.

I got a couple of little bubbles at one edge but hoping I can work around that.  The couple of times before my veneers were pretty uniform, but this mahogany was very warped.  I should have either put another 2 by 4 down the middle or added some weights.  But I think I lucked out.  If there are any bubbles in the middle, after cutting the stringer, I will clamp them with more epoxy.

Gdad, you do in fact rock.  I love that fish pump set up  I have bagged a half dozen boards with it and it is so much easier than my big honking vac pump.  Since they are so cheap I bought two.  In your debt for the guidance, thanks.  By the way, they make another pump that doesn’t have the throughput, but does have a better pull.  It has a thicker, single diaphram.

all the best 

If it works for you then you just made my day .    Do you mind if I ask which model that other one is?  

 

One more question…That basketball seems critical to the whole set up. I have a waterpolo ball, do you think that would work as well, or do I need to go purchase a basketball? Or could I use 20-30 tennis balls?

Any combination of sport balls will work as long as there is an equivilant volume as the basketball.

RH you are just hilarious. I wondered if anyone would catch that after I looked at the picture. My son in law cut it open and filled it with beach sand ( river sand won’t work on surfboards) to use as a workout prop. We toss it around for what passes as exercise. Sometimes. 

 

Ha. Spot on.