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Re: REFLECTOR: Bulkhead Installation



David,

> Is that really that big of a deal?  

I doubt it. The fuselage flange is just where the top and bottom halves happen
to come together.

> Also, when I layed it up (MG BH), about 2 hrs
> later I noticed some linear dry spots in the top layer in the bend part of
> the BH. Should I trash the hole thing and start over? Or is that not a 
> major problem.. Otherwise the layup is extra wet if anything. I wanted to be 
> sure nothing unravelled. 

Dry spots in your layups are definitely NOT good. But neither are super wet
spots. The method we adopted in all our fiberglass work was to wet out the
fiberglass on a piece of construction plastic, then transfer it to the place
where it's needed. 

If you do as we did and wet out the glass at the workbench, you have MUCH
better control of how much resin is in the lay-up, and can squeegee it until
it is completely uniform, and maybe a wee bit toward the dry side. 

Before you lay it in place on the airplane, you need to "prewet" the area of
the lay-up with a thin layer of resin. We use a cheap 1" or 2" paint brush for
this (the brush is trashed afterward, not cleaned). Next you put the prewet
fiberglass in place and dabble it into position with that same paintbrush. Lay
Peel Ply over top of the whole package, and dabble that into place. 

You do not want pools of resin in your lay-up. It adds weight and reduces
strength. Nor do you want your layups too dry. That saves weight, but also
reduces strength. The trick is to get the fiberglass strands as near to each
other as possible, and have just enough resin to fill the space between the
fibers. 

Practice makes perfect.

Dave Black
SW RG TopDoor