Board logo

Paint damage
locoboy - 13/1/04 at 12:30 PM

Hi all,

I am nearing the end of my donor parts clean up and am now concerned that when i put my nice new shiny front up rights onto the balljoints and torque up to the correct spec the nut will just peel off/ crack the paint around it.

Are there any tried and tested ways to avoid this, im sure this problem has the potential to rear its head in many other areas too, rear uprights, caliper bolts etc.

i dont want me time and effort ruined becasue of this if it is avoidable


JoelP - 13/1/04 at 01:32 PM

i think if the paint was on a well prepared surface (etched etc) then it shouldnt come off? maybe sand it thin where the nut will go and touch it up afterwards?


nick205 - 13/1/04 at 01:38 PM

Col,

I've found this problem as well and not found a good solution yet either. I spent a quiet moment F'ing & Flinding at the chipped paint on my wishbone brackets when I fitted the wishbones.

In the end I think you just have to get on with it and accept that some paint damage is unavoidable.

Anyone else got any suggestions???

Cheers

Nick


mackie - 13/1/04 at 01:59 PM

Washers made of fluff?


locoboy - 13/1/04 at 02:44 PM

i thought about maybe 2 washers under the nut with thin oil between them hopefully the lower surface of the bottom one will stay put on the (for example) upright and the top surface of the top one will stay in contact with the bottom of the nut leaving the two connecting faces of the washers to slide on each other.

Dont know if it will work but it may be better than just cranking up the nut and screwing up the nice paintwork.

Or........ just thought if this one, Mask the paint fit the nuts, and trim with a stanley knife trying only to cut the masking tape, leaving tape under the nut?

Workable or not?


kingr - 13/1/04 at 03:11 PM

Ummmm, maybe I'm missing something, but what's wrong with just using a single washer?

Kingr


Mix - 13/1/04 at 03:40 PM

Yep !!

Have to agree with Kingr, a single washer with a bit of lube between the nut and the washer. Oh! and if you study the washer you will see that it has normally been produced by stamping from sheet and as such one surface will have sharp edges and the other slightly rounded, assemble with the rounded side against the nut.

Mick


DaveFJ - 13/1/04 at 04:08 PM

quote:
Originally posted by Mix
Yep !!

Have to agree with Kingr, a single washer with a bit of lube between the nut and the washer. Oh! and if you study the washer you will see that it has normally been produced by stamping from sheet and as such one surface will have sharp edges and the other slightly rounded, assemble with the rounded side against the nut.

Mick


ERRR - NO

assemble with rounded side against chassis....


Peteff - 13/1/04 at 04:11 PM

Live with it, it's going to happen anyway. Keep some paint for touching up after you've done scratching it.

yours, Pete


Mix - 13/1/04 at 04:40 PM

If you assemble the washer with the rough side against the nut then the washer will probably spin with the nut as you tighten it, this may cause any finish to lift.
If you assemble the washer with it's smooth side against the nut the chances are that the washer will remain fixed in respect of the nut and therefore not cause so much damage to the finish.

But then again it's up to you.

Mick

There is also the option of 'wet assembly' whereby the final assembly is carried out before the surface finish, (in this case paint) is dry.

[Edited on 13/1/04 by Mix]


MikeR - 13/1/04 at 04:56 PM

I read a thing a while ago about torque and lubricant. Basically all torque figures are given when the thread doesn't have lube. Just wondering if lubing up the washer would affect the torque .....


DaveFJ - 13/1/04 at 05:01 PM

I see your point Mix BUT

if sharp edges are toward nut they MAY make the washer rotate at final tightening which would mena the nice smooth surface would rub against your paint and probably not mark it

However if you do it your way the washer WILL cut into the paint and damage the surface no matter what you do........


Mix - 13/1/04 at 05:23 PM

The degree of 'roughness' I am refering to is probably less than the thickness of a painted surface and hence I feel it is better to 'lock' the washer to the surface thus reducing the tendancy for it to tear the surface which would be the case if it rotated.

I suppose the jury's out on this one.

Mick


GO - 13/1/04 at 05:37 PM

MikeR, you beat me too it.

I'm no pro on these things but thats what I'd heard, that any form of lube will affect the torque settings and you're (I think) likely to over tighten it. By how much I've no idea, and probably depends on the kind of lube used. KY will probably have the biggest effect...


Peteff - 13/1/04 at 08:35 PM

I was taught that you don't lube what you don't want to disassemble often. So stuff like wheelnuts get copaslip, rest stays dry. Just my theory though.

yours, Pete.


flyingkiwi - 14/1/04 at 02:13 PM

having spent the last two days beating the poo out of an aircraft trying to remove a bolt that some plank has forgotten to grease I would go with a small amount of lube on the thread, it shouldn't affect the run down torque too much and if you ever have to take the part off again (maybe refishining paint that's been chipped off by stones????) it will make it a lot easier, nothing worse than having a seized nut to split!

But that's just what I'm gonna do!

chris


mackie - 14/1/04 at 02:29 PM

I was changing my brake disks the other day and one of the little retaining screws was rusted in and seemingly made from putty-grade steel, the screwdriver neatly ripped off the philips pattern head with little effort. So I drilled it. Pain in the ass and should have been coppaslipped.


Mk-Ninja - 14/1/04 at 03:08 PM

Im with Pete, to the point that you should realy use nylocs or thread lock on the bits you dont want to come loose.

Gordon


Mix - 14/1/04 at 04:19 PM

Lubing a thread and then torquing to a specific 'dry' value will result in more tensile load on the fastener than intended.

However there are obvious advantages to lubing threads.
One way to achieve the correct tensile load and lube the thread is to first torque the fastener 'dry', mark it's position, (witness mark), disassemble it, lube it and reassemble to the witness marks.
This proceedure should only be used for fasteners with positive locking such as split pins as lubing the thread will also make the fastener more likely to lose torque with vibration etc.

Should this not be an option then bolts should still be lubed to aid disassembly / prevent corrosion but the lube should be kept away from the portion of the thread in contact with the nut.

Mick