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1st time using T88

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Kyle Boatright

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Nov 11, 2012
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1,068
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Marietta, GA
One of the things I see repeatedly when talking about T-88 is "Don't over-clamp, you'll starve the joints."

Fair enough, but what is the appropriate amount of clamping pressure? How does one tell what is too much, too little, or just right?

I've never found a written spec.
 

TFF

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Apr 28, 2010
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13,826
Location
Memphis, TN
System 3 is not real specific; they agree with AC 43-13 that the minimum glue line should be .005" http://www.systemthree.com/reslibrary/literature/certwoodenaircraft.pdf but in repair .050" could be seen. From System 3 instruction book on their sight "Third, do not over-clamp. Epoxy resins require only contact pressure. Over-clamping can squeeze most of the adhesive out of the glue joint and the epoxy that is left is absorbed into the wood starving the joint. A glue-starved joint is very weak. Use only enough pressure to hold the joint immobile and keep the two surfaces in contact until the epoxy has set overnight at normal temperatures. Nails, screws, clamps, rubber bands, or staples can all be utilized.. Clamp just hard enough to close up the joint" http://www.systemthree.com/reslibrary/tds/t-88_tds.pdf says bond line thickness is not critical in reasonable made joints
 

skeeter_ca

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Jun 29, 2005
Messages
1,027
Location
Yucaipa, Ca
I use these small cheap ratchet bar clamps from Harbor Freight. They have them on sale sometimes for .99cents. They can't even squeeze hard enough to hurt on your finger but help to hold the part on nicely. The larger ones can hold pretty good but you don't have to use max pressure all the time.



skeeter
 
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