Brad330l

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The picture shows different off cuts from the fuselage of my Mustang I am building and some test pieces I attached to check bond strength etc. I used West Systems resin and preped some tests and just slapped on resin for some others. Also use some powder thickener on a couple of tests.

To say the least, I was not too impressed with any of the bonds after I simply lifted off or levered off the bits and pieces.

West systems is great so I have read and I just glassed my stabilizer with it and was happy but it does not seem to be the right stuff for general building for this material on my model.

A few facts;
Fuselage is 15+ years old and still smells a bit (hint to type of glass maybe)
I used the mix pumps from the West Systems kit and sturred well (it has all gone off ok)
When preping I used some (old) thinners then sanded/roughed with 80 grit and then cleaned again.

I need to glue in all the bits and pieces into my fuselage and need to know what to do.
Should I use Silicon sealant maybe and just use the West Systems for glassing the wings etc??

Brad

brad59

My Feedback: (32)

Brad,
Your fuselage is most likely made from Polyester or vinyl ester resin if it has a stong smell, particularly when you sand it. You should try using a good polyester adhesive/resin although West epoxy should adhere fairly well. I have had the same problem before with epoxy on polyester fuselages.Polyester will not work over epoxy. What are you using for a cleaner? They could be a problem.
Brad
Stan's Fiber Tech

soarrich

My Feedback: (98)

Brad
Polyester finishing coat resin has a wax in it, it float to the out side of the layup and forms a bearier between the air and the resin, You have to use some wax remover, ( auto paint store), then a light sanding, you bond should improve.

hoofty

What are you using to clean the parts? some thinners are oil based and leave a residue on the part. Isopropyl Alcohol usually works great as does MEK but make sure that you dont let any chemicals sit on your composite surfaces. always dry wipe then solvent wipe and dry wipe again to remove any solvet when cleaning / prepping for composite work.

Hoofty

P.S. Try the Polyester Resin on your part as stated above. might be the best thing if you have a poly part.

Troy-RCU

My Feedback: (1)

What exactly are you trying to bond into the fuselage? I have found that Goop is one of the best general adhesives when bonding to composite structures. It has a more aggresive bond than silicone and has a small amount of flex in it so it doesn't crack like an epoxy/poly.resin joint. Using epoxy or poly. resin is good in certain applications but it will always suffer in areas of high stress unless you have tied it in with cloth.

The yellow tint tsuggests to me it is most likely old polyester.

Brad330l

My Feedback: (1)

Thanks for the replys Guys,

What I want to achieve is to fit out my fuselage with formers,servo tray, wing hold down plate and bits and pieces for every thing else that has to be 'glued' in.

Troy, what is 'Goop'? Is it like our liquid nails?

I will try again with more preperation and try some Isopropyl Alcohol as a cleaner of the wax.

Brad

Brad330l

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Hi Brad,

I Think I have had a bit of success.
I used Enamel Thinners, 100% Liquid Hydrocarbons to clean the surface and it seemed to really bring out the weave of the cloth. I sanded and cleaned again and after 18 hours some of my test pieces have bonded quite well.

Do you think this thinners is ok, i mean does it have any oils in it?

I still think I will try some Isopropyl Alcohol or acetone to be sure.

Brad.

hoofty

the best advice is always trial and error. make some test pieces and prep with all the methods decribed above. mix your resin and lay up all of them at once from the same batch of resin. test the strength of the bond on all and go with what works best.

Let us know how it goes.

Hoofty

Troy-RCU

My Feedback: (1)

Clear liquid nails is very similar and that is a good one to try, too.