Primer for chipboard

[Jimk]

A 2 metre queue? Doesn't sound too bad - even before Saturday's change to 1m distancing...

[Jimk]

[Jimk]

Chipboard has visible er chips.... MDF being just glued together dust, doesn't have any visible chips...

https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.YaWeKmrRdGDM7r2YsxCtoAHaG-%26pid%3DApi&f=1

[Jimk]

A chipboard window ledge? Sure it's not MDF?

[Jimk]

Is it a floor? If so consider replacing for strength. Swollen chip sounds like it's already well on the way to turning back into weetabix...

[Scott]

Am I right in thinking it is best to use solvent (ie, not water) based primer for chipboard? I have found a tin of aluminium wood primer. Is there anything to stop me using that?

The background is that the chipboard was damaged (and swollen) and I had to rub it down so I don't want it to become swollen again.

Thanks

[Andrew]

Personally I would use something intended for another purpose, like IsoFlex Special Primer. This is intended for sealing concrete or sound felt roofing prior to coating with Isoflex itself.

If the chipboard has swollen and is going to be used as flooring then its strength will have been compromised, so a solvent-based substance to soak in and seal all the fibres would be a good idea.

Wickes sell Isoflex. Wilco used to do 'old fashioned' solvent wood primer (haven't been in for a while).

[Scott]

But this aluminium primer is solvent-based.

[Scott]

No, it's a window ledge. It is rock solid as I stood on it this morning for another reason. All that is wrong with it is that it is very slightly raised where the accident (leaking bottle) occurred and I wanted to make it level before repainting.

I found a tin of solvent based aluminium wood primer, which I thought would be ideal, but decided to check with some experts first.

[Scott]

How do I tell the difference? It is the colour of cardboard, and dull. It could well be MDF.

If it is MDF, what are the prospects of using Dulux solvent based aluminium wood primer?

[Andrew]

There are 'special' MDF primers, which presumably don't raise the 'grain' (or the fibres in the case of MDF). If you have already allowed some of it to get wet, maybe a small tin of ronseal wood hardener might be appropriate before using a primer.

[Scott]

On Wed, 1 Jul 2020 19:57:57 +0100 (GMT+01:00), Jimk [e-mail] wrote: [snip]

Its MDF. Sorry about the confusion.

[Scott]

On Wed, 1 Jul 2020 20:29:22 +0100, Andrew [e-mail] wrote: [snip]

The MDF is in surprisingly good condition considering it suffered from a leaking bottle of some chemical cleaning agent that dissolved the paint. It is now dry and solid.

I am happy to join the two metre queue and buy a tin of MDF primer but before doing so I just wondered what would stop me using the aluminium wood primer I already have (and will be using on some wood), which is solvent based. I know water is to be avoided.

[PeterC]

Looking at following posts and seeing that you are using solvent-based paint, I would suggest that you try P5(?) chipboard and water-based primer. Solvent might attack the binding substance and water will attack wheetabix. I used P5 in the loft; some of it got rather wet when it was stacked outside (no rain forcast...!) but even the exposed innards weren't affected. The surface is so hard that I had to use a drill to start the countersink for the screw holes. Note: where ther's a danger of a drill 'picking up', a masonary bit does a good job of 'scraping' a hole.

[charles]

I met a 2 metre distance queue at a local decorators merchant, on Monday. Two people ahead of me, it didn't take too long and it wasn't raining.

[tabbypurr]

You can use any oil based primer.

NT

[Brian Gaff (Sofa)]

How did the damp get in the first place, through the edges. If its near water I ended up putting those plastic edging strips over the edges and part way down the sides. Its a pity makers of units don't use some kind of water resistant material fo or units so exposed. Brian

[Andrew]

Including an aerosol can of car primer !.

But I think he is keen to avoid an unnecessary trip and use aluminium primer.

Dulux say is suitable for all hardwood and softwoods, MDF is just sawdust 'glued' together, so I guess it won't hurt. It's main use is for resinous hardwoods or old creosoted timber (!!).

[Scott]

No, it was a bottle of some cleaning chemical with a tiny hole in it. The pool did not spread very far, nowhere near the edges. It did, however strip off all the paint. The MDF is now fully dry and showing no signs of damage other than a very small amount of swelling, which I intend to sand down.

[Scott]

Thanks, all. I'm going to go with what I have and use the aluminium staff.