I find the tools fairly decent but the mandrels are so shitty, they strip out or strip the rivnut or get jammed up and twisted during install resulting in failed nuts. Generally, I'm not a huge "hack" guy either, but after a while, I found using the tools bulky and cumbersome. It just became easier, faster and more reliable to do them without the tool.
Just my 2 cents though. Also, a toothed lock washer works like a charm too.
I have used my rivnut tool on cars and various things around the house (for me it was a tool that once I had it I found a heap of uses for it); and I will sort of second what blockrocker said. The tool I have is pretty cumbersome and if inexperienced you can strip the threads and all sorts of issues...but after a bit of using and getting used to the tool I find it OK. I have never used a hack method to install one; but I’ve never been pushed for space either. The particular tool I have is about 300mm long (12 inches) when in use so that could be a problem for some.
It also cost like $140 Australian as well...it definitely has paid for itself though.
Not really what the OP was querying but interesting anyway. If you can use Velcro (as in ‘if it’s strong enough for what you want to do’) then absolutely 100% use that. Easiest solution for sure.
I’ve used the hack method before, but I ended up just buying the proper rivnut tool from Amazon.
When I tried the hack method my dumb a$$ used stainless steel nuts and bolts. For those that don’t know (like me prior to this experience) stainless steel is actually pretty soft. Everything ended up working out, but it took forever and there were quite a few mishaps
Yeah...not so much related to the stainless steel side of things (as I haven’t used any that I can remember); but just in general there (at least for me) was a definite ‘learning curve’ in actually using the rivnut tool. I actually used it first on an install I did for a guy and wound up threading about half the nuts! It is sometimes a little difficult to tell when it has locked in place and if you ‘go further’ you are just going to strip threads. No need to be a brainiac, just be careful to start.
Just as an off topic note... I have used the tool on home made furniture, an outdoor wooden/steel fence...sure it has use as a car install tool, but I have found it fantastic for plenty of other jobs. I always have a selection of rivnuts in the box because it’s amazing when it helps out. Just a thought if any guys build other stuff around the house or whatever as well as car audio.
Peace
No... even rivnut can rip out in a crash, Velcro is a bit unwise.
Velcro, like glue, is only strong as one long as one does not peel it. Up starting wiht one side or corner. Even in glued systems it is common to use a rivit on the edges to prevent peeling, as the Pell strength is the achillies heel of glue or Velcro.
OP if you have a steel car, use steel or stainless rivnuts.
However stainless will gall with a stainless screw, so you will need anti-siege por some thread lube.
If you are really paranoid, and cone nut could be put on the underside.
Some POR15, or undercoating, or paint can aid in rust prevention.
I should’ve mentioned that simplicity in sound used industrial strength Velcro to hold down the amp rack on at least one of their builds - this was why I mentioned it. I’m not sure how it worked out or if the amp rack was connected to an enclosure mounted to the vehicle in other locations.
Really? Interesting. Not sure that I was taught (or I can’t remember is probably more to the point!) ‘peeling failures’ at university...but I remember the shear strength of bolts. An M8 bolt isn’t going to shear until you get close to putting a metric tonne plus (2200 pounds) load on it. I guess what you say about the threads pulling out seems logical at that rate!
I certainly super glued the Velcro to the doors of my car when installing the Velcro to hold the Mass Loaded Vinyl because the typical Velcro adhesive was weak as piss. However I have my sub box stuck to the fitted carpet type stuff top of my boot/trunk with a single line of Velcro about 300mm long (glued and stapled to the box). It isn’t moving anywhere (I know because I tried to move it the other day and it refused sufficiently for me to give up!).
It would take a hell of a car crash to move my sub box...and I don’t think I’d be concerned about the box if that kind of impact occurred...
Yeah, i dunno...
If the Velcro was near one side (front), and just a single strip, then the mass and impact could cause tthe box to lever off of the Velcro?
But it certainly does not want to release when one wants it to.
Having a box flying around in an accident is a real thing with camping refrigerators (Eskis in Australia from the word Eskimo, and chilly-bin in NZ, because it is bin that is chilly.), so it is not planned, but worth planning for.
I worked with a couple of really seasoned materials engineers, and they used peel tests for epoxies and adhesive tapes... and I think there is a Mil-Spec for the tests.
That metric tonne for an M8 sounds right. It is a lot, but if the bolts were along the front, and there is a moment arm to the centre of mass, and the snout of the car plowes into a wall, then it too could lever against the bolts and break them in tensile before they would ever fail in sheer. Hopefully it would just buckle the trunk and stay attached.
I could see a shop doing it in a test/demo car as a temporary thing.
Personally I would use the rivnuts and call it a day, and then save the Velcro for cable tiedowns, carpet, and smaller things. But I am not an expert in crashes or safety.
Here's the build I referenced above which included securing the foundation board for the amp rack.
https://www.diymobileaudio.com/threa.../#post-2163819
Originally Posted by simplicityinsound, post: 2163819, member: 1820Originally Posted by simplicityinsound, post: 2163819, member: 1820
So, this is definitely a show car, and I'm sure it isn't driven that much. Also, the velcro is just part of the system to secure everything.
Last edited by Chris12; 02-19-2021 at 07:34 AM.