How to fix MDF kitchen cabinets after over-sanding?

Question

Hi All,

I recently removed all of our kitchen cabinets doors and drawer fronts as the laminate had peeled in areas.

I rremoved handles, used a heat gun to remove laminate, removed adhesive, lightly sanded and primed. I used a water based primer (sold to me at Bunnings but not suitable for mdf) and it failed. Two coats, and it scratched off with my finger nail.

My Issue is that we've over sanded the mdf cabinet doors, especially the routered details to remove the primer. To the point on some areas the cnc cut detail has been damaged. Also marks from using a scraper to remove primer. MDF feels very fibrous.

I'm not sure what to do. Sanding seems to be taking hours as quite a bit of hand sanding has been required to get scratches out of the routered area.

I guess I'm asking if this is beyond repair?

Our cabinets are non standard, so off the shelf doors aren't an option. Local cabinet maker has 8 - 12 week wait for replacement doors - minimum.

Is it worth putting the hours in on sanding? I've got 16 doors and 5 drawer fronts to navigate. Any tips on streamlining the process. I've got a ryobi palm sander,  and ryobi multi tool with precision sanding head. I've been using sanding sponge with removable sanding sheets for the routed areas.

I've got correct primer and aqua enamel tinted ready to go. Unsure if it's worth precious hours of work if it's going to look like rubbish.

I'm doing this solo as husband is out of action undergoing cancer treatment, and not sure if it's worth persevering on. Local cabinet maker said it wasn't worth sending off to get two-pac painted and I need new doors.

Or do I just go ahead and prime and paint? Will the imperfections be very noticeable?

Noyade · Answer

G'day @RebeccaB

I think you've done a magnificent job getting back to raw MDF. Was the hot air-gun the most useful tool?

"Or do I just go ahead and prime and paint? Will the imperfections be very noticeable?"

That's what I personally would be doing - if the finish is noticeable, call it rustic. If people complain - slap them. You've done extremely well under difficult circumstances and I sincerely hope life soon improves for you both.

Cheers.

Dave-1 · Answer

Good Evening @RebeccaB

I would also like to offer best wishes for you husband.

I think you have done a very decent job with the doors. Thats a lot of sanding and detail work.

I wonder if using this

UNi-PRO 500g Smooth Coat Skim Filler - 500g

would help seal the mdf and give it an easier surface to paint. You could test it out on the back of a door and see.?

Money verse time you spend would be the ballance I would choose. New doors = ???? Your effort to get the doors into a shape you are happy with = over half way there id say.

Its a hard call but i like the story of the effort you are putting into it. :)

Dave

Nailbag · Answer

Hi @RebeccaB

Firstly my best wishes for your husband's recovery.

If the original lamination is what I am thinking, it's was more of a formed folded plastic heat glued to the doors and drawer faces. I saw this for the first time myself last year where it was delaminating. The entire kitchen was falling apart and was a very lengthy process of using a contact adhesive and tapes to refasten it as best as possible.

Now for your situation, there are no shortcuts here as it's purely down to manual labour. The palm sander will help of the flat surfaces only. To ensure there is nothing visible through any of the finish layers the surface needs to be smooth to the touch. I run my hands over surfaces that I'm finishing with my eyes closed to feel for imperfections and then work on getting them out. You will then need to use a primer prior to painting.

It really is a hell of a lot of work. And if new cabinet fronts is an affordable option my advice would be to take it.

Nailbag