Layup problem

[coolamber]

I need some advice on how to repair some layup issues. I did the big layup on the fuselage sides and when I was done stippling out all the bubbles I layed on my layer of peel ply. Once the peel ply was down I was pretty much unable to do any further inspection.

 

Well during cure a few areas developed bubbles between the foam and fiberglass. Maybe I missed them during the layup. MGS and blue foam seems to make them more difficult to notice. Anyway some are just the small 1mm or less bubbles that I cannot really worry about.For the larger ones, I was considering using a 18 gauge hypodermic and syringe from the unglassed side to back fill the spaces with epoxy. I will do this when I pop the sides from the jigs. Is this a valid repair technique?

 

One of the areas that has bubbles is within the 10" radius of the canard attachment point, so the plans seem to indicate this is a critical area. For the inspection 10% rule, does the rejection mean that 10% of a 6"x6" square area is air, or 10% of the area has portions with air?

 

Thanks much!

 

Coolamber

[steve]

the best way is to cut out the bad spot and overlap a patch.

if you try to re-glue it must be sanded first or it wont stick

i have them same as you, and i wont fix them untill much later

so much is cut or changed from were you are now.

50% of your bobo's mite be on the floor

[Marc Zeitlin]

.... I was considering using a 18 gauge hypodermic and syringe from the unglassed side to back fill the spaces with epoxy. I will do this when I pop the sides from the jigs. Is this a valid repair technique?

The plans explain what to do in cases like this - look at the inspection and repair section - don't remember the chapter #. I think that the plans recommend drilling a small hole into the bubble and injecting the epoxy from the front, but if you can find the bubble from the back side, that should work, too.

 

...For the inspection 10% rule, does the rejection mean that 10% of a 6"x6" square area is air, or 10% of the area has portions with air?

I always interpreted it to mean that 10% of the area could be air bubbles.

[coolamber]

 

I always interpreted it to mean that 10% of the area could be air bubbles.

Well I am below that 10%, I will be well below that after the repairs, so I would "think" that any repair would be more structurally sound than a patch.

 

Thanks!

[coolamber]

Edit please ignore double post from accidental reload (sorry)

[Neverquit]

Syringes work great for those. The trick is to drill two holes. One for the air to exit. I tried drilling one hole and it just doesn't work well. If you fill from the foam side, be sure you do the same. If your fill is vertical, get a patch of duct tape or something to keep it in. Big bubbles (I say 1" or larger) get out the dremel and go by the plans.

[coolamber]

Syringes work great for those. The trick is to drill two holes. One for the air to exit. I tried drilling one hole and it just doesn't work well. If you fill from the foam side, be sure you do the same. If your fill is vertical, get a patch of duct tape or something to keep it in. Big bubbles (I say 1" or larger) get out the dremel and go by the plans.

Thankfully all of the bubbles are under 1/4"