Lauan issues

[jtsarby]

I really don't like the looks of the lauan. I am going to seal my weekender with Aluthane. I put some on a test piece and the grain is really showing through. I would rather have a smooth finish. I feel like my only option is to sand the top layer, which is incredibly thin, down until everything is smooth. I guess it is time for a belt sander. It will take forever with my orbital.

[3822sean]

belt sander on the face of lauan sounds scary

[Woodbutcher]

Don't do it. Sanding off the top layer with out messing up the second layer is tough. Plus what makes you thing layer 2 is better. Is it texture you don't like or the grain pattern. If the grain is to strong you can try a stain controller to mute it some. If it's the texture try a heavier bodied polyureathane like Varathane. A few good coats sanding with 320 between coats will fill the grain. Just my 2 cents.

[eamarquardt]

belt sander on the face of lauan sounds scary

I agree, belt sanders can be pretty "agressive".

Better to get some high solids primer, let it dry well, and use a hand sanding block. Never seen a belt sander in an auto body shop.

Hope this helps.

Cheers,

Gus

[jtsarby]

It is the texture. I am going for a smooth finish. The lauan has an almost raised grain finish. I used my orbital sander on one small spot and it took the first layer off and revealed a smooth layer underneath. Thanks for the advice on the belt sander. A friend suggested a skim coat of bondo. I dont like that idea and it sounds like a lot of work. Should I prime first or use the Aluthane epoxy first?

[eamarquardt]

It is the texture. I am going for a smooth finish. The lauan has an almost raised grain finish. I used my orbital sander on one small spot and it took the first layer off and revealed a smooth layer underneath. Thanks for the advice on the belt sander. A friend suggested a skim coat of bondo. I dont like that idea and it sounds like a lot of work. Should I prime first or use the Aluthane epoxy first?

I dunno. Try some "test strips" first then decide.

Hope this helps.

Cheers,

Gus

[48Rob]

When you apply a finish to raw wood, or plywood, it does what is called "raising the grain".
Something like the hair standing up on your arm.
It is normal.
It/any product should not be expected to give "final" results with just one coating.
It sounds like you are trying to make cheap Luan look like perfectly smooth aluminum?
A light sanding after each coat of material applied will smooth things out.
By the 3rd-5th coat, you will have a very smooth surface...
For perfection, it may take 6-8 coats, with meticulous sanding and scuffing between coats to remove imperfections.
By light sanding, I'm talking about 220-320 grip in a palm sander, or with a block by hand, no aggressive belt sanders, or grits.
Sand for the first 3-4 coats, then scuff between coats.
"Luan" is generally used as an underlayment, and isn't designed to be used for finish work, though with care you can make it look pretty good.

Rob

[len19070]

Rob is spot on with his advise.

I've even made Sheathing grade plywood on other projects look presentable with this method.

Happy Trails

Len

[Dusty82]

I've done a lot of painted finishes on cabinets and Gus and Rob are absolutely right. Sand the surface smooth with 150 grit on a random orbit sander, then spray your primer. Hand sand that with 220 or finer sand paper on a sanding block, then prime it again. Repeat the prime and sand routine until you get a nice smooth surface. The primer will fill the grain and you should end up with a nice smooth finish.

We used this technique on a kitchen cabinet set that was finished in white Imron (yes, Imron) and it turned out mirror smooth. If I remember correctly, we used 4 coats of primer, sanding between each coat. For the final coat of primer before spraying the Imron, we used 320 grit paper.

[jtsarby]

Thanks for the info. Should I prime first or seal first?

[eamarquardt]

Thanks for the info. Should I prime first or seal first?

I think I'd seal then multiple coats of primer.

Cheers,

Gus