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2
- #1
KootK
Structural
- Oct 16, 2001
- 18,599
I spoke to a Lindapter representative today about using blind bolts in an exterior HSS application. Was wondering about gasket / no gasket etc and general best practices. I figured that I'd share this with the gang given that:
a) Lindapter gave me a very informative response, even if some of the suggestions are common durability dogma.
b) I'm not sure how you'd find all this out without asking the question yourself. Hopefully it saves someone some time in the future.
c) I had it typed into OneNote for my records anyhow so low effort on my part.
The info:
1) No manufacturer guarantee of corrosion performance of course.
2) They have standard galvanized, HDG, and stainless.
3) They recommend HDG for apps outside the building envelope.
4) They don’t recommend stainless unless attaching to aluminum or something. Bimetallic corrosion issues with carbon steel and high prices.
5) For other reasons, sizes 5/8 and larger actually have a neoprene gasket built in which will expand into the annular gap a bit. For this reason, they typically recommend 5/8” or larger in exterior applications.
6) They recommend against additional gaskets for sealing. Firstly, they worry about UV deterioration. Secondly, I guess the extra flexibility and potential development of a gap with the eventual loss of the gasket actually compromises capacity.
7) They did some informal testing in a coastal application. Tidal with alternating submersion and exposure to open air. No water intrusion after 6 months with just the basic HDG and no gasket.
8) They recommend weep holes in the HSS which is generally good practice of course.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
a) Lindapter gave me a very informative response, even if some of the suggestions are common durability dogma.
b) I'm not sure how you'd find all this out without asking the question yourself. Hopefully it saves someone some time in the future.
c) I had it typed into OneNote for my records anyhow so low effort on my part.
The info:
1) No manufacturer guarantee of corrosion performance of course.
2) They have standard galvanized, HDG, and stainless.
3) They recommend HDG for apps outside the building envelope.
4) They don’t recommend stainless unless attaching to aluminum or something. Bimetallic corrosion issues with carbon steel and high prices.
5) For other reasons, sizes 5/8 and larger actually have a neoprene gasket built in which will expand into the annular gap a bit. For this reason, they typically recommend 5/8” or larger in exterior applications.
6) They recommend against additional gaskets for sealing. Firstly, they worry about UV deterioration. Secondly, I guess the extra flexibility and potential development of a gap with the eventual loss of the gasket actually compromises capacity.
7) They did some informal testing in a coastal application. Tidal with alternating submersion and exposure to open air. No water intrusion after 6 months with just the basic HDG and no gasket.
8) They recommend weep holes in the HSS which is generally good practice of course.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
