Duct Tape residue removal from fiberglass

[rnbraud]

Hi all,

 

We have all read about removing duct tape residue from our plexiglass canopies.

 

Now I have a question about removing duct tape residue from cured fiberglass.

 

I just pulled off the duct tape layer that I applied while building the canopy frame. I need to apply some additon plies of fiberglass over the longerons onto the sides of the fuse. However, when I pulled off the duct tape, it left a lot of that gummy residue.

 

I have searched the archives and found suggestions of Goof-Off, Acetone, Paint thinner, MEK and the like.

 

What I am curious about is what these cleaners will do to the underlying cured epoxy. How will it affect the subsequent plies of fiberglass?

 

It would seem Goof-Off or Eucalyptus would leave an oily residue.

 

It would seem MEK, Paint Thinner or Acetone would dissolve the epoxy, well maybe just a little, but it would seem to soften it.

 

What is the best way to remove duct tape residue off of cured fiberglass if I intend to apply more plies of fiberglass over the affected area?

[Wayne Hicks]

I see you've already got a bunch of answers from your query to the email discussion groups. A non-solvent approach is to get one of those large erasers and rub the glue off the fiberglass. Go to Office Max and get several of those coarse grey erasers. They look like small match boxes. It will take a while, but it will take the glue off fast. The eraser causes the glue to roll up on itself.

 

Then follow through with a good, rough sanding as the others have suggested.

 

Curious, how long was the duct tape on the fiberglass before it was pulled off? I found it must be removed ASAP. And as others have suggested, I use black electrical tape whenever possible. I learned to avoid using duct tape.

[rnbraud]

Hello Wayne,

 

Thanks for the reply. I will add the rubber eraser to my list of "non-solvent" approaches. Sounds like a winner.

 

The duct tape is called out in the plans. Either Uli Walthers or the standard plans to build up spacing for the canopy frame for the bottom layups. I think I must have put on 5 or 6 layers.

 

Unfortunately, I didn't realize at the time I would be leaving it on the fuse for about 2 months. Otherwise I would have removed it sooner.

 

Live and learn!

 

Thanks for the tip.

 

Later.

[Wayne Hicks]

Yes, there are several places in the plans when duct tape is left on for long periods of time. I know you know this, but for others out there we use duct tape because (1) it's cheap; (2) it's a good mold release; and (3) it can be used to build up thicknesses to mold space for layups that will come later. I use the trick of applying one layer of electrical tape first, then applying the duct tape when I know it might be a while before it'll come back off.

[Lynn Erickson]

Yes, there are several places in the plans when duct tape is left on for long periods of time. I know you know this, but for others out there we use duct tape because (1) it's cheap; (2) it's a good mold release; and (3) it can be used to build up thicknesses to mold space for layups that will come later. I use the trick of applying one layer of electrical tape first, then applying the duct tape when I know it might be a while before it'll come back off.

One of the tapes I used is plumbers tape it is the same basically as electrical tape but comes in 2" wide is very cheep and comes in 5, 10 and 20 mill thick. when you need to build up even more thickness use a layer of the tape with a layer of foam double sided tape covered by the tape . epoxy will not stick to plumbers tape and it gives a smooth finish.

[rnbraud]

As a follow up to the Duct Tape residue issue.

 

Last night while digging through my "tool drawer" I came across a pink eraser and thought let me give it a quick try. I also noticed I had one of those belt sander cleaner thingys. You know, a big ole rubber eraser thingy.

 

Well, the pencil eraser did work but required a lot of work.

 

I then tried the sandpaper cleaner thingy, and WOW, works great.

 

I mean really great. The fiberglass is spotless and it doesn't require much effort.

 

The best way is to rub it in one direction. Then pick off the rolled up duct tape glue.

 

Thanks for all the tips.

 

Now on to drilling out my main spar! Aaaaaah!

[longez360]

A rag with eucalyptus oil works great. Moves all sticky residues. Flush with water afterward.

[brainfart]

Having a background in chemistry I have to give my 2 cents worth:

 

I'd rather use a volatile solvent, because it's volatile! Meaning it will evaporate without leaving any residue whatsoever. Even when you use an alcohol (alcohols are bad for epoxies on long term exposure) it will be gone just seconds or a minute after you're done wiping off the glue, and your epoxy will not be affected whatsoever.

When using solvents with higher boiling points like the aforementioned eucalyptus oil or others like orange oil which seem to become rather popular lately for environmental reasons these oils will leave some residue on the part for much longer, meaning that residue has time to migrate into the epoxy. These oils usually have boiling points in excess of 200°C. They do not evaporate easily! And since they aren't water soluble you cannot easily wash them off with water (like you can with acetone or alcohols).

 

Does all this actually matter? Probably not. I'd still rather use a rag soaked in acetone, wipe that stuff off and not worry about the epoxy being contaminated by a persistent solvent.