Thread: countersink how to

Hi fastig doesn't sound like fun, a couple of questions for you: how is the meranti to be finished, painted, oiled, other ? you said it was getting fixed to hardwood and masonry, does this mean the scotia goes between hardwood and masonry everywhere or is it between ceiling and masonry and ceiling and hardwood in other places? is the masonry face brickwork or rendered brickwork or other. possible options include sikaflex glue and short nd brad nails, or obviously c brads into the ceiling. if screwing is the only option then a pilot and countersinking bit would be useful for fixing to the hardwood.

Check out 'countersink drill bits" - they pre-drill and countersink in one go. Something like this: SYDNEY TOOLS - Carba-Tec 7 Piece Countersink Drill Bit Set

Hi Sii and Ilya, thanks heaps for your input.

The moulding will be stained, then satin clear.

I have 2 situations in my basement makeover:
1. moulding in the corner between ceiling and masonry wall,
2. when there is a bearer along the wall, then 2 mouldings as on the attached image.

Masonry is rendered brick.

I think Sikaflex may be a bit messy and a bit expensive. And may not be possible as both mouldings and render may be curved/warped.
Is fixing to gyprock ceiling reliable enough?

Countersink bits! I didn't know about such a thing. This may be a good option, thank you very much. What pilot did you mean though?

I would not screw the mouldings into place as it takes too long and then you will have a lot of ugly filling to do before staining. i would nail and glue the scotia in. on the hardwood you could use panel pin nails say 20/30mm long for a 20mm scotia, but you will need to pilot or pre drill slightly smaller first then hammer the nails in. if you angle the nails in correctly you wont need to fix to the render at all, and the same against the gyprock ceiling. Sounds like a mornings work for a carpenter. Dont forget to scribe your butt joins as it should be done or you could just cheat and mitre the corners.

Pre-drill and use nails, yes that's another idea... I understand that this would prevent scotia from splitting, and prevent nails from bending in hardwood, is this correct?
Sorry I'm not a professional, so what makes the panel pin nails special in this case? Are they stronger than other nails? I've tried several types, they all bend with hardwood.
Thank you very much Sii.

Glue is the way to go with this task,the fast grab liquid nails works well,put a bead on the moulding ,push to contact then pull apart and leave for a little then push up to finished position,you may need the odd brick pushed against it to hold for a short while.
Do your final finish before fixing,that only leaves the odd touch up at the joints to do at the end.
I have used this method on the exterior render finish many times when needing a trim from the wall to a tiled deck,in that case I used the waterproof version.

Thanks nrb.
Gluing moulding to render - the render will be painted with water based paint before doing moulding, will the glue reliably bond to paint then?
Gluing moulding to hardwood bearer - the bearer is very old and is dark brown in color, probably treated with some stuff back 60 years ago. Will the glue work there?
Would you use the particular brand "Liquid Nails" by Selleys or any similar product will do?

If I choose not to use glue, is this a good idea: drill reder with 5mm drill 35mm deep, insert wooden dowels 6x30 instead of plastic plugs, pre-drill moulding so that it doesn't split, then nail moulding to dowels. Will this work?

Liquid nails is fine and will be ok on a painted surface just make sure that the surface,render or timber is not loose or flaky,use the fast grab.
As to plugging and drilling I would agree that is one way to go but it's a lot of work and you will most likely not like the final result as you really won't hide all the places where you have screwed.
Lets see what other members think?

fast grab liquid nails. Tool off most of the squeeze out and clean up with a damp rag before it dries. Use jam sticks to clamp it in place if you can.

I agree with the use of adhesive. If you are worried about getting it to stay in place while the glue grabs, a few well placed brads (need a nail gun) or fine nails (pre drill and half fix the nails first so you can put it in place then simply move around and bang them in) will work fine. If you have a few friends available, invite them over to stand around for 5 mins while the glue goes off.

Screwing would make the moulding look like it has the measles. As hard as you try to fill and match, it will never look the same. And the holes would be big, so it would be really obvious.

Keep in mind that, unless your bearer and render are square and true, you will get some inevitable gaps between the moulding and the wall. This will be particularly noticeable if the joint between the roof and bearer and bearer and wall is 90 degrees.

Trav

Thanks everyone for your input. Will proceed with adhesive. Will post the results soon!