Welcome to the Bunnings Workshop community @richardk. It's sensational to have you join us, and many thanks for your question about pre-oiled Merbau timber.
Those are not silly questions at all.
If you have concerns about tannin bleed from our pre-oiled products, a thorough and regular hose down during the first few days will assist in flushing excess tannin away and minimise subsequent staining. You could leave them out in the rain, but a few hose-downs will normally do it. Make sure to place the timber on the grass so the tannins don't leak onto any light-coloured surfaces. For more information, check out this guide.
You don't need to strip off the existing oil to apply new oil. You would apply the new oil after the tannin removal process.
Please let me know if you have any questions.
Thanks heaps for the response and the link Mitchell.
The guide specifically says not to leave it out in the weather, so a few vigorous hosing-downs it is!
Just one more follow-up question: i assume the second top-coat oiling be done after the cuts are made (so the end-bit gets oi)l. But should this be done after it is attached to the frame (after screws have gone in) Or before attaching it to the frame?
Thanks v. much.
From a painting point of view, it would be easier to oil the panel before you fix it in place. This will allow you to oil it back-to-back and not get anything else accidentally covered in oil.
Please keep us updated with your project, we look forward to seeing your picket fence oiled and assembled.