How to remove spun rivnuts?

[DMC-81]

Hi there,

I have one spun rivnut on the radiator shroud. Question: What's the best way to delicately remove it to avoid any unnecessary damage to the fiberglass. Also, is there a way to loosen or dissolve the galvanic corrosion?

Thanks.

[DMC5180]

It somewhat depends on what state it's in. Is it empty or does it have a seized bolt in it? Is the shroud still on the car?

If the bolt is still in the rivnut, I prefer to drill the head off. I use a box end wrench to hold the head from spinning while I center drill the head. I like to start with an 3/32 or 1/8 bit to pilot a starter hole about 1/8 - 3/16 deep. Then upsize to a 3/16 drill bit and drill into that hole. It should pop the head off. If at this point, the shroud can be removed leaving just the rivnut with thread stub sticking out your best bet is to get a dremel tool with cut-off wheel and carefully grind away every bit of the rivnut that is proud of the surface. Once flush or close to it. You knock the remnant piece into the blind cavity. Now you just install a new rivnut with the proper tool. Or use the long bolt w/ nut & washer method.

[PJ Grady Inc.]

Hi there,

I have one spun rivnut on the radiator shroud. Question: What's the best way to delicately remove it to avoid any unnecessary damage to the fiberglass. Also, is there a way to loosen or dissolve the galvanic corrosion?

Thanks.

A straight diegrinder with a carborundum cutting wheel (AKA a "muffler cutter") is the only way to go.
Trying to drill out a spinning rivnut is an exercise in futility akin to "p.....g in the wind"!
Rob

[David T]

A straight diegrinder with a carborundum cutting wheel (AKA a "muffler cutter") is the only way to go.
Trying to drill out a spinning rivnut is an exercise in futility akin to "p.....g in the wind"!
Rob

There are only 2 ways, drilling or grinding. As Rob points out to drill it you must prevent it from spinning if possible. I have had some luck sometimes by drilling it at an angle so even if it spins you can cut the head off. The sure-fire method if you have enough room is to cut/grind it. If you don't have a die grinder you can do it with a Dremal and some patience and a lot of cutting disks. If you damage the fiberglass you can always put a new insert in with some washers or repair the fiberglass.

[PJ Grady Inc.]

There are only 2 ways, drilling or grinding. As Rob points out to drill it you must prevent it from spinning if possible. I have had some luck sometimes by drilling it at an angle so even if it spins you can cut the head off. The sure-fire method if you have enough room is to cut/grind it. If you don't have a die grinder you can do it with a Dremal and some patience and a lot of cutting disks. If you damage the fiberglass you can always put a new insert in with some washers or repair the fiberglass.

Grinding is 5 times faster and safer for the fiberglass too. I long ago perfected my technique of sliding the grinding wheel across the face of the bolt head/rivnut until its flush with the F.G. and then tap it through the mtg hole. No fuss, quick, and no damage if you do it right.
Rob

[DMC5180]

Trying to drill out a spinning rivnut is an exercise in futility akin to "p.....g in the wind"!
Rob

Rob,

I never said, you drill the rivnut out. I only use the drill to remove the head of the fastener depending on the situation.

The washer fluid bucket is a good example. I had a bolt / rivnut spin in a tight area. I used a drill to pop the head.
Once the bucket and tank could be removed, I was able to grip the back of the rivnut with a small vise grip and was able to grip the protruding nub with another vise grip and back it out. I took a rivnut tool and re-cinched all of the rivnuts. Along the way I did replace a few rivnuts in the trunk area.


Dennis

[DMC5180]

Grinding is 5 times faster and safer for the fiberglass too. I long ago perfected my technique of sliding the grinding wheel across the face of the bolt head/rivnut until its flush with the F.G. and then tap it through the mtg hole. No fuss, quick, and no damage if you do it right.
Rob

Agreed


Dennis

[PJ Grady Inc.]

Rob,

I never said, you drill the rivnut out. I only use the drill to remove the head of the fastener depending on the situation.

The washer fluid bucket is a good example. I had a bolt / rivnut spin in a tight area. I used a drill to pop the head.
Once the bucket and tank could be removed, I was able to grip the back of the rivnut with a small vise grip and was able to grip the protruding nub with another vise grip and back it out. I took a rivnut tool and re-cinched all of the rivnuts. Along the way I did replace a few rivnuts in the trunk area.


Dennis

I got it Dennis about holding the bolt head. If there is room (The big if) then grinding is faster and safer. If you have to come at it straight on then you gotta do what you gotta do right?
Rob

[DMC5180]

I got it Dennis about holding the bolt head. If there is room (The big if) then grinding is faster and safer. If you have to come at it straight on then you gotta do what you gotta do right?
Rob

Yup

[DMC-81]

Great, thanks for the techniques everybody. As for the situation of the rivnut, the shroud is removed, but the stainless steel bolt and fender washer are stuck in there. I might try drilling the head first to get the big washer out of the way, and then grind. Wish me luck! :wrenchin:

[skill]

On a few projects ago, I had a similar issue. I tackled it by clamping down the back end of the nut with Vise Grips/ pliers and drilled out the head from the top. Clean deal and no damage.

[DMC-81]

I thought I'd report back. I was able to remove the 2 rivnuts from the lower radiator shroud today...

Before:
37517

Cut away:
37518

Poked into the inner cavity:
37519

Actually there was a hole straight thorough the inner foam to the relief cavity for the front indicator lights so I was able to poke them all the way and remove them as I also have the whole front end off currently.....
37520

Thanks again for the tips on doing this job.