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Paint before attaching Bodywork
Angel Acevedo - 10/8/17 at 04:11 PM

To all...
Due to not receiving a reply on a thread hijack, - see http://www.locostbuilders.co.uk/viewthread.php?tid=208724, and not able to find an answer, please share your opinions.

Point is.
Chassis work/welding is still ongoing, even though most of chassis is complete, I still have a myriad of Brackets to weld on but want to start attaching bodywork to the sections of the Chassis that are already complete as are cockpit and passenger side of same.

A few years ago, I painted the Chassis with a High Solids Epoxy Primer which is pretty much as good as new save a few scratches and dings from normal working around the chassis.

Question is:
What would be better prior to attaching Bodywork with rivets and Polyurethane adhesive? Both consider skipping paint where brackets or any other components will be welded.
- Paint chassis fuly?
- Paint chassis on all surfaces except where the adhesive will bond to it?

Reasoning behind the second which I´m inclined to is that if I paint I am adding another Substrate interface to go wrong therefore less desirable.

Thanks in advance for your comments
Angel Acevedo


ste - 10/8/17 at 05:19 PM

in my opinion, it would be best to bond directly to the steel. Obviously it will need a very good clean and de-grease, then ensure the surface is keyed and finally wiped down with IPA or similar. bond on your panels, then paint any bare steel not covered.

If you are supplementing it with rivets too, then there is no reason why you can't paint the chassis first, as the rivets will prevent it coming off.

On mine, i have painted my chassis first, and the bodywork is bonded on with a PU adhesive but supplemented with rivets

hope this helps


ste - 10/8/17 at 05:20 PM

Regarding brackets to be added later, you can always sand away any paint prior to welding anything on, easier to do that than sand away rust.

Or you can buy 'weld through' paints


Angel Acevedo - 10/8/17 at 05:58 PM

quote:
Originally posted by ste
in my opinion, it would be best to bond directly to the steel. Obviously it will need a very good clean and de-grease, then ensure the surface is keyed and finally wiped down with IPA or similar. bond on your panels, then paint any bare steel not covered.

If you are supplementing it with rivets too, then there is no reason why you can't paint the chassis first, as the rivets will prevent it coming off.

On mine, i have painted my chassis first, and the bodywork is bonded on with a PU adhesive but supplemented with rivets

hope this helps


quote:
Originally posted by ste
Regarding brackets to be added later, you can always sand away any paint prior to welding anything on, easier to do that than sand away rust.

Or you can buy 'weld through' paints


Direct to steel no longer possible, keying and degreasing AND removing 5 plus years of dust is mandatory.
question is again, if adding another layer of paint between primer and adhesive is a good idea or not.

As I am painting with an Alkyd Enamel, I should have no problem blending painted areas with the ones that will be painted after welding any additions. So that is not a concern, at least for now.
Thanks for your comments and best regards
AA
PS: Keep them coming... this weekend I should weld the structure that will hold my Steering column and Transmission mount. With these two, I can cover both sides of the cockpit...


jacko - 10/8/17 at 08:03 PM

I would paint it and just give it a very light rub down not to go though the paint before using tiger sealer
If you don't the sealer never covers all the metal so leaves unprotected areas for rust
jacko