GF Enduro water-based primer for MDF

[williamrschneider]

I recently purchased some General Finishes Enduro water-based primer for a speaker project, and found to my surprise that the label specifically recommends it for MDF. It's formulated for spray equipment, and the label claims it has a high-solids content and sands easily. I bought it to prime some Baltic Birch because I didn't want to spray solvent-based primers in my garage.





If it does the things claimed on the label, it will be good. It's costly though - this gallon can was about $62 plus shipping from Homestead Finishing. It also comes in white, but it costs even more (~$77 + shipping)

Has anyone here used it on MDF? How well does it handle end grain without a seal coat of shellac or a glue wash?

I guess that I'll find out for myself with some tests once the rain goes away (4 to 5 days of it are forecast), but if someone has any experience with it, I'd appreciate their comments.

[fastbike1]

Re: GF Enduro water-based primer for MDF

Haven't seen that before. Very happy w/ every other GF product (and there are many in my finish cabinet). Really curious to see how you like it.

[Soundslike]

Re: GF Enduro water-based primer for MDF

I'd be interested too... Please keep us posted.

[williamrschneider]

Re: GF Enduro water-based primer for MDF

I'm updating this with some observations about the primer. It is not for everyone because it requires a spraygun to apply.

On smaller parts, I used to use Rustoleum sandable automotive primer. It dries quicky, but most importantly, it sands nicely.

The General Finishes Enduro Undercoat is water based, and does sand nicely - EXCEPT that it is a little more finicky about sandpaper used. I had great luck with
Abranet mesh sanding disks on my random orbital sander, and a cheapie sponge sanding pad of about 240 grit, but not so much with the yellow 3M 320 grit sanding sponges. While the finish didn't corn the 3M product, I had to knock the dust from it about every half minute of sanding. The dust is very fine, and fills up the sponge. The mesh product, like the Energizer bunny, just kept going. I used only one disk of 320 grit in the RO sander for 6 coats of the primer.

I WILL use this in the future. A can of Rustoleum just won't do on large surfaces, and I've always been a little wary of using it for a water-borne top coat applied afterward. I always let it dry many days before following up with the water-based product.

Now the pictures...

Here's a picture of the 1st coat vs. the 5th coat. I sanded using mostly 320 grit between coats. This is Baltic birch, and you can see that the woodgrain has been completely smoothed...



After the 4th coat of primer, and using Bondo spot putty for the minor imperfections...



Below is a picture showing the Baltic birch woofer box, and the baffle bracket made of both MDF and BB plywood parts...



And here is a close up of the top of the woofer box and the MDF base of the baffle bracket (missing some screws, etc., - this was a dry run to check for appearance)



If you have access to a spray gun, try this primer. I got mine from Homestead Finishing (Jeff Jewitt's business) based in Cleveland.

[john trials]

Re: GF Enduro water-based primer for MDF

Wow. You do nice work!

[donradick]

Re: GF Enduro water-based primer for MDF

Very beautiful as usual!

[xsundown]

Re: GF Enduro water-based primer for MDF

Ohhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh hhhhhhhhhhhhhhhhhhhhhhhhh I like that! That's nice.

[bobbarkto]

Re: GF Enduro water-based primer for MDF

Looks pretty good, Bill. Might have to try it sometime.

I'm just finishing one of the boxes I mentioned starting.. oh, last year! Cherry and satin black baffle. Nice combo as your work so elegantly shows.

[williamrschneider]

Re: GF Enduro water-based primer for MDF

Thanks for the comments. guys. I can't design speakers, so I put my energy into building them attractively. I really admire how talented many of you are on the technical side.

Bob... thanks for all your help along the way with my finishing questions. It was a few years ago that I realized that you really knew what you were talking about from your helpful posts. I sometimes wonder how or where you gained all of your finishing experience.

With this primer, I might have all the ingredients in place to do a nice finishing job without worry.

[REM.Audio]

Re: GF Enduro water-based primer for MDF

Thanks for the comments. guys. I can't design speakers, so I put my energy into building them attractively. I really admire how talented many of you are on the technical side.

[Bob... thanks for all your help along the way with my finishing questions. It was a few years ago that I realized that you really knew what you were talking about from your helpful posts. I sometimes wonder how or where you gained all of your finishing experience.]

With this primer, I might have all the ingredients in place to do a nice finishing job without worry.

+10

[Soundslike]

Re: GF Enduro water-based primer for MDF

Very nice. Tastefully and skillfully done. I'll be giving that primer a try.

[bkeane1259]

Re: GF Enduro water-based primer for MDF

That's an outstanding cabinet.....really makes me feel like a unskilled wannabe woodworker...thanks for that. :p

Seriously tho...I have a noob question. How is the black box attached to the hardwood frame? That IS hardwood right....(shakes head and really feels like a noob)

[williamrschneider]

Re: GF Enduro water-based primer for MDF

The woofer box is intentionally NOT attached to the hardwood parts to prevent transmitted vibrations. Linkwitz designs usually have some isolation or damping scheme like the rear midrange mount on the Orions , or before that, the original constrained layer damped baffle in the first iterations.

The cherry "bridge" straddles the woofer box without contact - except perhaps at the very bottom where the sides of the bridge "feet" may rest against it. I'll have some F3 felt there mostly to prevent damage to the final finish when the two parts are nestled together, but it will provide some vibration resistance too.

The wide upright panels on the bridge are not solid cherry, but Baltic birch plywood with cherry veneer. The rest of the wood you see is cherry.

[r-carpenter]

Re: GF Enduro water-based primer for MDF

very nice work!
I'd be curious to hear your review of this loudspeaker.

[williamrschneider]

Re: GF Enduro water-based primer for MDF

very nice work!
I'd be curious to hear your review of this loudspeaker.

You're going to trust the builder's judgment about sound? ;)

I'll be sure to post my opinions once they are finished.