thehiddenproject wrote:
Is there a problem about using aluminum rivets into a steel frame?
Basically no. Some more info for consideration.
There is a shelf life to aerospace fasteners when the bag is opened. Most blind rivet sleeves are 5052 or 5056 alloys aluminum due to there formability. That grade is of aluminum posses better corrosion resitance than say 2xxx or 7xxx. these fasteners are typically also cadmium plated AND have a cetol alcohol lubrication. This coating also provides a degree of corrosion resitance in addition to its lubrication properties. Manufacturers recommend keeping fasteners in closed bags until use to protect the coating.
5056 or 5052 being common blind rivet materials should offer that protection in there alloys. I see no issue using these. It is common practice to install rivets "wet" with primer or sealant to protect the hole base metals, I second zetecs thoughts.
Sealant only under the head and primer under the head and on the sleeve. Sealant on the mandrel or on the sleeve may cause early pin break or "hydraulic" in the hole and cause imcomplete hole fill.. thats not my opinion, but manufactures guidance. A little goes a long way and too much goes the wrong way.
As for the mandrel, you are most likely to see a trail of rust from the unprotected fractured mandrel on the head of the rivet.. this is negligible in most cases, even on aircraft.
Do it, you may consider giving the joint more longevity with a "wet" instal and or using a plated fastener.
Andrew