REFLECTOR: seal bulkheads before baffles?

[John Tvedte]

TEC,
 
Well - I'd have to re-read the manual - but when we sealed our strakes, the baffles were treated just like they were bulkheads - yes, we glassed the mouse holes, and made sure they didn't have any pinholes.  That meant digging some of the foam out- and filling with epoxy/micro - and then glassing.  If you have a pin hole on a bulkhead - it would allow fuel to migrate into the foam as well.  
 
Strakes are one of the most critical construction areas of the Velocity - methods have changed somewhat over the years - i.e. Jeffco - also it is suggested to seal the strakes when closing with Jeffco - that means use Jeffco to glue the top of the strake on - 'gray goo' Aeropoxy is used on the strake to spar area - and outside the tank sealing area on the leading edge.
 
On the pre-seal - what we did is used a lightweight bid - and covered the entire fuel area of the strake - in our case, 3 of the strakes were made without peel ply - so had very rough surface -and pinholes.  We had to grind the stitching and sand them to get a 'bite' - and then put the lightweight bid and peel ply on.  So - that is what we did to seal the strakes properly.

________________________________

From: reflector-bounces at tvbf.org on behalf of HYTEC45 at aol.com
Sent: Thu 8/2/2007 11:34 AM
To: reflector at tvbf.org
Subject: Re: REFLECTOR: seal bulkheads before baffles?


In a message dated 8/2/2007 7:05:02 A.M. Pacific Standard Time, bdtopp at comcast.net writes:

	
	TEC,
	   I don't believe anybody is sealing the portion of the strake that is directly under a bulkhead or baffle.  I know I didn't.  In theory, fuel should never see that area if you have a really good coat of Jeffco on everything including a nice bead on the top of the baffles and bulkheads when closing out the strake.
	 
	Bruce

Bruce,
 
I also did not pre-seal below the baffles prior to installation, and have not had any leaks in 11 years.  However, I have always worried about it, and wish I did.  A bulkhead and a baffle are two different things (unless things have changes in the plans).  A bulkhead's core will never see fuel as it is stopped by it's inner skin, where a baffle's inner foam core will see fuel(unless things have changed and all edges including the mouse holes are tapped and sealed), and can migrate through it to the surface, approximately 9/16" wide, area of the inner strake skin the baffle is sitting on.  While the perimeter and face of a bulkhead can be sealed as it's exposed, the area of the strake skin the baffle is sitting on cannot.  I worried after I closed my strakes about this, and just lucked out that there were no pin holes in the factories lay ups.  I like the pre-seal with peal ply before installing the baffles.  Wish I did.  If you have put fuel in with no leaks, we both should go to Vegas.
TEC



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