2008 kia sportage 2.0 crdi headgasket and other issues.

After some opinions, the car came to me 3 months after I had diagnosed head gasket failure, by this time it had overheated on more than one occasion.
I estimated the repair for the head gasket replacement. on removal I noted that pistons 1 and 4 had the indent of one intake valve on each piston, also the camshaft and some followers were damaged. I spoke with the customer and gave him another estimate for additional works required. He has asked me to put it back together so he can trade it in. My concern is that I can not warrantee the work so feel I should create a waiver to cover myself. How would you proceed?

I would note it on the invoice, just as you have described.

A head gasket issue was diagnosed, 3 months prior to repair attempt. Removal of the cylinder head revealed further damage. Owner declined repairs. No warranty.

I was thinking the same, or a waiver before I rebuild it, I have been in the trade for many years and this is the first time I have encountered this, guess I have been lucky with my customers.

That's a tough spot.
I'd be VERY tempted to put the cylinder head in the trunk with all the other parts and tow it back to his house. I'd even eat the tow bill...

Thought had crossed my mined as well. although he is into it for the strip down at the minute.

Refusing to put it back together is a sure-fire way to make an unhappy customer. I would only do that if it were a safety issue.

If he is aware of the damage, and knowingly chooses to decline proper repair, document it, have him sign it, and carry on. You have a much better chance of keeping a happy customer (and getting paid) that way.

The key is to document it and have the customer sign it.