Afternoon All,
I'm fixing my ally cockpit edging with M5 round head cap screws and can't decide whether to drill and tap the top chassis tube or use
Rivnuts. Would there be sufficient metal thickness in the top tube to take a thread if I tapped them.
Any advice welcolm.
Regards
David
Normal rule of thumb / guideline is to get minimum 3 threads. If pitch is 0.75 you need 2.25mm steel thickness. You probs wont have that. However i
doubt if the fixings will take any load so it might work. Can you not rivet? If not then rivnuts are the safe option as you wont have any risk of
stripping the threads when assembling.
By cockpit edging i assume you are talking about the side panels? Unless you mean the internal panels. What about using Wurth Bond&Seal for the
panels that you will never need to remove again?? Ive used this for GRP side panels and it is the proverbial sh1t to a blanket! Highly recommended.
Darren,
It's the 30mm wide aluminium strips that sit on top of the cockpit rail.
Thanks
David
They'll be the ones that sometimes also extend up the curved rear arch profile bit to the top where the roll bar sits. Im going to fix these in
place with rivets on mine. Id suggest that you will want these to be fixed quite well as you will support yourself on these when getting in and out of
the car. A bit of bond&seal under them will also make them very secure (with rivets) for the belts and braces approach.
If you use bond and seal and find some of its gets onto aesthetic areas i have found that acetone cleans it off. Take care to test the acetone on a
hidden area in case it will affect the gel coat etc. (I bought acetone in small bottles for a few penniew from my local chemists).
Did you know that acetone can also be used to bond ABS plastic. Shaving some abs and mixing with acetone in the bottle can also make abs filler (takes
a couple of days to disolve fully) - handy to know if you want to join to bits at right angles (ie transmission tunnel or boot area).
I used rivnuts for this.
Make sure they are in nice and tight. I used M8 ones and they dont have much of a lip on them so its hard to get them tight enough without pulling
them through. A few of them werent tight enough and once i had tighetned them up i had to undo a couple, they just span as the riv nut wasnt tight
enough, this left me with a bolt caught in a rivnut and no way of getting it out, so i had to cut the ali out and chop the bolts off. Then get some
more ali trim
Very annoying and time consuming!!
We just tapped the chassis, its more than strong enough for holding the trim on,
unless you've got it mega thick the trim would probably bend before the screws pulled out of the thread.
Also wouldn't the rivnuts stand proud of the chassis and be a waste of money and weight (negligable but it all adds up!)
I am hoping to laminate many layors of 1/16 inch maple or ash to make a trim that surrounds the cockpit. it will be time consuming but should make a
nice edge.
Dale