[TBFGhost]

I can't find the post where we were talking about butting or scarffing field joints...I said I used to scarf 22.5 or 45, but now I do butt joints on paint grade. I promised a shot of an un painted joint. I finnaly rememebered to get one. This is a 5" MDF crown.

 

[texastutt]

I just did my first butted two weeks ago, the painters there tomorrow, and I'll have a look at it and see, but I was impressed with it especially since it was 5/8" thick 5-1/2" Homely and Desperate special MDF.

 

[katoman]

That butt joint is quite visible. I've tried it with bisquits and glue, was back a year later and could see the joint. ( fixed them )

Went back to the 45 mitre joint, I think the larger glue surface, plus nailing through both pieces makes the difference.

Especialy with wood, as opposed to MDF. After painting, I don't want to see any joint anywhere.

 

[WarnerConstInc.]

If painted trim and butt joints, butter the joint with some fast n' final or a bit of drywall mud.
It will ooze out and you can wipe the excess off and come back when it sets up and lightly hand sand. Seem is gone.

You really want to get carried away use a domino.
I hardley need to butt because I can get most trim profiles from the mill shop up to 20' lengths.

 

[TBFGhost]

The Butt joint is just faster for me then a scarf joint. the Scarf joint is harder to install solo. if I am worried about the joint opening up I will take 1/4" MDF and glue/staple it to the back of the joint...there is no way that joint is moving then...

That butt joint is quite visible. After painting, I don't want to see any joint anywhere.

That joint is without paint and with out any prep...some sanding it will be gone...most of the time the paint crew that follows me will sand the joints, prime them with oil, and sand them again with 220 before they paint...joint is 100% gone at that point...

Here is a painted butt joint at my folk home, my father did the prep and paint, so it was not as well as a paint crew... you can see the joint in the photo b/c I but the camera right on it with the flash. In normal viewing light you have a hard time seeing it, and if you didn't know where to look, forget about it.

 

[TBFGhost]

Here is a photo of it from the same angle, with and with out flash...

 

[TBFGhost]

Here is a 45* scarf on MDF crown, you can't see the joint in normal light, but again, put the camera on Macro setting, put the camera within 2 feet of the joint, turn on the flash....and you can see it.