Stud finder to find roof struts?

[Sebulba]

Hello all,

Quick question.  I am getting ready to install solar panels on my roof.  I want to attach to the side to side roof struts and not just the skin.  Will a standard stud finder work to find these or do you have a better idea?

Thanks

Seb

[luvrbus]

The roof will have rivets at every roof truss the roof attaches to,easy to see,a stud finder is not going to be of much use   

[Glennman]

I used a small very strong magnet. You can move it from side to side and locate the struts and/or the strut flanges. It is very effective at finding the center of the flange, or any steel (except for stainless). Worked great for me when I installed my solar system. My '02 MCI only has a limited number of rivets so it wasn't as clear as you would think.

[luvrbus]

I used a small very strong magnet. You can move it from side to side and locate the struts and/or the strut flanges. It is very effective at finding the center of the flange, or any steel (except for stainless). Worked great for me when I installed my solar system. My '02 MCI only has a limited number of rivets so it wasn't as clear as you would think.

Magnets work,I pop a string line from the riviets on the curve on the sides,I wouldn't drill for screws anyway,the 3M 5100 adhesive will hold the brackets forever,that is what is used to hold the sides and roof on the MCI D   

[peterbylt]

On our 96A3 we lined ours up using the roof rivets.

Drilled down through the frames between the rivets and used cross nuts (like rivnuts only stronger)

While bolting everything down I also applied copious amounts of Sikaflex 252 to bond and seal.

Brackets and panels are still as solid and leak free as the day I put them up a few years ago. 

Peter

[windtrader]

I had two goes at securing struts for panels on the roof. First attempt was a fail. I thought adhesive would be enough but a couple panels flew off and landed right on I5. The specs seemed fine, I ground the roof patch to bare metal and glued it up using 5200 or similar. Upon examining the failed joint, it dawned on me that galvanized brackets don't work to the galvanized coating. I did not grind the glue side and you can see how it failed.Round two, I used rivnuts and 1/4" stainless bolts on the front set of stainless brackets as those get more air uplift, don't ask me how I know. There are three sets of brackets on each pair of panels and square tubing rails. At the midspan and rear, I just used self tapping screws. I did drill the starter holes as that metal really strong. I saw no reason for rivnuts, just overkill in my mind.

[Glennman]

Magnets work,I pop a string line from the riviets on the curve on the sides,I wouldn't drill for screws anyway,the 3M 5100 adhesive will hold the brackets forever,that is what is used to hold the sides and roof on the MCI D

My roof only has a couple of rivets showing on one flange, so the other flange (other side of the hat channel) doesn't have any rivets showing, so the magnet was handy finding that other flange. I doubled up by using (as luvrbus says) 3M 5100 along with drilling holes in the flanges and threading the holes. Between the bolts and the 5100, it's not going anywhere.

[luvrbus]

The 3M 5100 if you follow directions whatever you use it on is there forever.Van introduced me to a product called Sure Seal made in Canada for plastic bumper repair and it is not cheap when you use it the plastic is not going to move or break,it makes JB Weld like a kids glue a amazing product to glue plastic to metal or repair broken plastic

[Iceni John]

I used circular magnets to find the actual edges of each roof rib;  the rivets aren't necessarily along the center of each rib!   I would roll the magnet towards the rib's edge, and it's very obvious when it reaches the edge.   Easy!

John

[ktmossman]

The more modern MCIs do not rivet the roof to the struts on the main surface.  They anchor the edges where it wraps under the drip-rail, but use sikaflex on the top struts.

[luvrbus]

The more modern MCIs do not rivet the roof to the struts on the main surface.  They anchor the edges where it wraps under the drip-rail, but use sikaflex on the top struts.

That is correct but the structs are riveted to the uprights under the drip rail that is where I get the location to pop a chalk line