My father is a HOARDER, from food to tools, etc... Perhaps dementia?

You have to ask yourself if the hoarding has been his entire adult life or if it's something new. If it's new, is it the result of trauma?? Also, some seniors hoard certain things although they don't have dementia, and some people with dementia do hoard as a symptom.

Ra Bonn I agree with you but I'd like to add that when doing the donating take a pix on cell phone preferrably with the logo of the charity visible & them in forefront to remind them of their generosity - this could short cut some arguments later

Hoarding is a disorder fraught with loads of denial. They will watch the Hoarding TV shows and say, "At least I'm not that bad," though frequently they are. I am an adult child of a hoarder. (We even have a Facebook group!) Hoarding comes in all varieties. The one that may be of interest here is Diogenes Syndrome. Here is a Wikipedia link. It's also known as senile squalor syndrome. wikipedia.org/wiki/Diogenes_syndrome. Also here is a link for diagnosis of hoarding levels. There are five levels, just like for tornadoes. My mother was a level 3 hoarder while I was young, then a level 4 when I was in college. By the time she passed away she was a level 5, with dead animals hidden places waiting "to be buried." So it can get VERY serious. You have to draw lines and pick your battles. But do your research. Here are the five levels: post-gazette.com/local/north/2010/12/02/Levels-of-hoarding-some-guidelines-for-recognizing-the-problem/stories/201012020349. There are a number of graphs/charts on line that are easier to print/read.

My mother was a hoarder what I did for her kitchen and my dad tools that was left I told her that we could place them in a box and that I could cal some people to come over to see what we could sell and it took a while but I manage to make it work.

I can relate to the question and all the responses. Mom is going on 96 and has been hoarding probably since my brother and I moved out after high school and college! Once our rooms were vacant, they became available for stuff, and once they were full, it just started filling up the rest of the house. This is a 4B/3b 4200+/- sf house. Mostly, it isn’t garbage, per se, most of her collections of stuff are boxed and marked what’s in it. Some things still out in the open. Brother and I don’t know what to do. She has 10-20-30 year old newspapers and clippings that has “good information”! When brother tries to get rid of anything, she has a fit.
At this point, he and I have talked about not upsetting her. At her age, she’s becoming much more forgetful. She doesn’t drive. My brother does all the grunt work since I do not live in the area any longer. He goes over to her house daily. He cares for her meals, her meds, her doctor visits, etc, etc.............. We will have to call in a specialist! ...for her and the house. Also my brother and I both have a tendency, he more than me, but my husband helps me stay in control. Brother is a single guy, so he’s basically a runaway train!

Small steps. There was an article in yesterday's paper that suggested going through related things. For example, sort through sweaters by putting them all together and tossing the ones that don't bring joy. You know what I mean. But instead of going room by room, go category by category. That's what I am doing. Jewelry is next, then photos. My father, who has dementia, could not do this by himself. He can't find anything right in front of him. Nor will he be interested in doing this with me, even though it will make his life easier.

My mother-in-law is what we call a neat hoarder. She puts things from toilet paper rolls and tissues in boxes and then stacks the boxes up in her 3 bed room house. Lucky for us she is staying in our house for now and we can control what she tries to save. Twice a week one of goes to her house and sorts through boxes and throw things away that have no value. She also can't drive and is a home tv shopper but we don't have those channels on our TV. (so she thinks) and did I mention she too has dementia to?

“He keeps the spaces he doesn’t use fairly clean.”

That doesn’t sound like a hoarder. They kind of fill up any space they have.

“.. BUT, boats, cars, trucks, food (COSTCO)...”

That’s most men! Since, he’s using those vehicles, I’m guessing he’s pretty active and that’s a good thing. With regards to unkempt places, maybe, he’s tired or didn’t get the time or just a procrastinator. Can you hire a help to clean them out on a periodical basis?

“He lives alone”.

That’s the crux of the problem! Some repeatedly try and fail miserably to replace people with things. Can you arrange a date or take a vacation together? A place away from home may instill a fresh perspective on life. You can’t change anyone’s behavior, but you can avail new opportunities to them to induce such a change.

“If he can’t FIND something he HAS, he just buys another..”

If he doesn’t have the time to bother searching and has money to throw around, what’s the issue? It’s not ideal, but not a big issue. It more looks like an organizational problem. Again a maid would help.  If you’re doubting a memory issue like dementia or Alzheimer, arrange for a brain scan to rule it out. 

“How do I approach this issue when he “Feels” the items are “worth” something even if he doesn’t use them or they go BAD, (food)..”

How about once in few months, suggest a yard sale or guilt him into a food donation drive and clean the place out?

A professional such as a social worker usually has to come there and work with the hoarder as it is a mental illness.