I'm totally new to woodworking and as my first project I want to make a small table. I'm planning to paint it so the wood material will not be visible. And I want to bevel the edges using a router. I'm trying to keep it on a budget since it is just a practice. There are several board materials I can use with almost the same price. OSB, plywood, MDF, and hardboard. I read online that mdf is stronger than plywood and OSB. But I can't find any info on the strength of hardboard. So my question is, if I use two layers of 1/4 inch hardboard, would it make a stronger tabletop than 1/2 inch MDF? Thanks.
ANYTHING is better than MDF for your project as it is a terrible material for furniture, especially custom made furniture. Also you can't use a router on MDF - well you can but it will not turn out well.
So you can probably find pine, oak and cedar at big box. All stronger than mdf, all suitable. If you are painting, pine is my go to as you can cover it without seeing the grains. (there are many many other choices of solid wood planks if you want to order or go to lumber yard. I just answered the question in a wood that is reasonably easy to find.)
I've used MDF to make a table top. (the legs, and upper frame were pine) the strength was fine (I jumped up and down on it etc) I didn't paint it because I wasn't going to do anything wet on it, and I didn't want to have to wait for the paint to cure (which can take weeks after it has dried) if you don't wait things will stick to the paint if left on the table.
if you do paint it use a two part paint because they cure rapidly.
Plywood and OSB are both stronger than MDF, but they have more surface texture.
Gluing two sheets of hardboard together without using a table-sized press sounds like a tricky task.
Yes. Hardboard will not expand as easily as Mdf which will also absorb liquid spills more easily. Mdf is not as compressed as hardboard. However, Mdf is good for many projects. It has clean edges which can be painted and look the same as the rest of the panel . With raw wood or plywood the edges look terrible if you leave them exposed. It really depends on how your table is going to be used . I would worry about the hardboard curling downwards on the edges of it hangs over at all. I've not seen hardboard used for a table top. I really don't know which one would me best, they both have good features, good luck!!
Depending on the type of table, tempered hardboard OVER a sheet of MDF can make an excellent table or work surface.
Now, it will be very utilitarian and probably not eye catching as a dining table... but with a couple coats of polyurethane it makes an excellent bench top, outfeed, cutting, or assembly table...maybe even house furniture too, maybe.
However, I would still put some kind of boarder around it and not attempt to keep a chamfered edge on the HDF/MDF. This could be anything from a 1×2 strip of maple, oak, etc. OR half of a nice exotic species of deck board, or even a decent grade of SPF (assuming southern yellow pine or Douglas fir, which hold up better). The softwood will get dinged up, but maybe you won't mind if you like to put your feet up on the coffee table!