Is Proseal 870 Appropriate?

[RWoodard]

I tried the search function and found only 3 entries that only tangentially mention Proseal 870. I’m in the process of repairing a fuel tank leak on my RV3 and a friend is offering a supply of Proseal 870. He’s a very experienced (30 years+) airline mechanic, but doesn’t know if this is appropriate for 100LL use.

I tried a google search and found product spec sheets that say it “resists” exposure to 100LL, but that language doesn’t sound very solid to me. Vans doesn’t specifically reference a part number (other than their own), but zooming in on a picture shows 890 in at least one of their offerings.

Can anybody help me out with this? I’d just order from Vans, but with all their problems in timely shipping, I don’t want to risk it.

Thanks!

 

[cvairwerks]

It's really a corrosion inhibitor rather than a fuel barrier. It will tolerate avgas to an extent, it's not formulated for that as a primary use. You can download the tech data from the page here:

P/S 870® Corrosion Inhibitive Sealant - 6oz Semkit™

High-Performance Sealant for Aerospace Applications Ultimate Protection from Corrosion PPG PS/870 corrosion inhibitive sealant provides unparalleled protection against harsh elements in aerospace applications. Its service temperature range from -65°F to 250°F with intermittent excursions up to...

anz.ppgaerospacestore.com

 

[fixnflyguy]

I do ALOT of sealing. These are the three I will use. PR870 is not one of them. See the spec sheets for 1422,1440, and 890. I assemble with "B" thickness on fay surfaces and voids, then topcoat with "A" thicknes (brushable) . I don't recommend using PR870. I've been working with these products for 45 plus years.

 

[olyolson]

Rob,

Have you tried getting some small supplies from one of the local FBOs? The FBOs here usually have some of the small ones in stock.

 

[RWoodard]

Ok. Thanks for all the quick answers. I’ll decline the offer from my airline buddy and find the right stuff on my own. I knew I could count on VAF!

 

[fixnflyguy]

Ok. Thanks for all the quick answers. I’ll decline the offer from my airline buddy and find the right stuff on my own. I knew I could count on VAF!

Mention to your airline buddy the 3 flavors I recommended...to my local friends, I am the "airline buddy", and his J.O.B. probably utilizes the others as well. I haul home all the expired sealant , often by the case, which works fine for a looong time after the printed date.

 

[DanH]

Technically speaking, none of the common polysulfide sealants are intended for use with avgas. The sealant standard is AMS-S-8802. The qualification tests are all done using AMS 2629F Jet Reference Fluid (JRF), a standardized proxy for jet fuels.

On the practical side, do whatever Bill says!

 

[RWoodard]

My airline buddy was able to score some 890B for me. He sent me a pic of their hazmat disposal barrel today and I was able to score a bunch of other useful chemicals, too. His employer doesn’t mind him taking them home because the products are expired and can’t be used anyway.

Score for me!