[alpinelakespilot2000]

Van's instructions for the windscreen fairing indicate that mild phosphoric acid seems to assist the adhesion of windscreen fiberglass to the aluminum skin. Have others used this and, if so, where does one go to buy it locally?

 

[shuttle]

Haven't reached that point yet so cannot comment on how effective it is. However, phosphoric acid seems readily available on Ebay. It appears to be commonly used for rust removal.

 

[lorne green]

Phosphoric acid -

Isn't Alumiprep diluted phosphoric acid?
"Alumiprep 33" ?

 

[fl-mike]

Ospho. Available at Home Depot, etc.

 

[Danny7]

coke/ pepsi. Ha ha, just a joke unless some chemist says all hte other ingredients are good

 

[douglassmt]

No

I didn't use it, just heavily scuffed both plexi and alum. with 50 grit and wiped with MEK. Won't hurt anything though, I have some 75% H2PO4 and played with it on alum. No bubbling or violent reaction, just a slow cleansing. Weaker Phosph Acid would have less effect.

 

[Ralph Inkster]

If you choose to use Alumiprep or similar etching solution, do not let it dry on the surface, rinse off with lots of water.
My prefered technique though would be to aggresively scuff with course paper then wipe plexi down with Naptha, skin down with MEK, lay first 2 layers of glass, let cure, install some pop rivets for good measure, then lay further layers of glass on top.