Internal/External mdf

by Tony
(United kingdom)

I have sent for some mdf 15cm (h) and 18mm (d) letters which will spell 2 names.
The mdf is stated has being internal but I wish to mount these names outside.
They are classed as unfinished.
How do I go about sealing and painting? (1 blue,1 pink)so that they will last, maybe 2-3 years, or more hopefully.

Comments for Internal/External mdf

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Nov 04, 2016
Painting MDF for exterior use
by: Shawn

Hi Tony,

If you give the letters a good sanding and then apply two coats of top quality exterior primer, along with at least two coats of exterior paint, you should get a minimum of three or more years out of them.

Be sure to lightly sand between coats of primer/paint and check that the wood is entirely coated with each application.

Also, if you put holes in the letters, to hang them, the holes need to be sealed too (with silicone). Otherwise (to be on the safe side) glue the letters up (with an exterior construction adhesive).

As a final note, give your letters a good inspection at least a couple times a year and scrape or sand away any pealing paint that you may see (no matter how minor) then prime the sanded areas and touch them up with your leftover paint.

Keep in mind though, that due to the weathering of the letters, your leftover paint may not be an exact match to the paint that's on the letters.

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