How to fix puffed out flake board?

Hi there, water damage can be difficult to fix if it's extensive. Here's an article that may help - https://www.hunker.com/12609045/repairing-a-water-damaged-mdf-baseboard but since you mention that sanding makes it worse, it might be beyond repair. To make a silicone mold of we use this recipe - https://acraftymix.com/blog/two-ingredient-mold/. You can try it on the undamaged flake boards and cast new ones on cement or clay. I hope you come right

Here's a link that discusses how to deal with water-damaged particle board:

https://www.waterdamageplus.com/wood/particle-board-water-damage/

Take off door. glue and clamp it down!

Particle swells up with moisture, it also looses it's integrity and strength, it is best to just replace it. You might try to find a suitable replacement at Restores, they have contractors items there.

Sorry but Redcatcec is right when you see the "puffy" look that means moisture has got into the particle board. There are ways to try and save it but that is sort of like putting out a fire with a glass of water.

Check with you local Good Will mine has 75% off their furniture twice a year. That is 75% of their prices.

here is more info

https://www.waterdamageplus.com/wood/particle-board-water-damage/

Once this type board has gotten wet, it causes the swelling you are seeing. The only real solution is to remove and replace. If you cannot do that, you can try glue and press between vises until glue dries.

Once particleboard gets wet it usually swells and flakes off. Cheap solution is to sand the area, fill with wood filler and sand smooth. Here is how you can make a mold for trim.

https://www.hometalk.com/diy/repair/furniture/jewelry-box-with-missing-molding-fixed-with-bondo-41391681

https://www.hometalk.com/diy/bedroom/furniture/how-to-rescue-an-antique-dresser-that-was-destined-for-the-trash-44250170

https://www.hometalk.com/diy/bedroom/furniture/how-to-bring-antique-back-to-life-and-rebuild-broken-feet-44287246

Thank you for this information, William! I will look at these sites!

This video may be a help, hopefully this works for you - it's for repairing water damaged particle board

https://www.youtube.com/watch?v=-ksXKllMaf8

Have you tried to just paint the spots were it cameoff

Ok this is not really a solution, but if it's just the cabinets under the sink, can you add a sink skirt to cover the damaged area? They're all the rage now! Then you can fix the pieces for structure but it doesn't need to be pretty. Just a thought.

This resource may help you out https://suggesthow.com/how-to-repair-particle-board-water-damage/.