Author Topic: T-Cut or not T-Cut? ( that is the question...)  (Read 1006 times)

Offline Chipswitheverything

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T-Cut or not T-Cut? ( that is the question...)
« on: June 09, 2023, 09:30:33 PM »
    I'm doing some brush painting of engine castings, using brushing enamel paint, having already filled, primed and flattened down the surface of the castings to a decent smooth finish for receiving the colour coats. I have done the same process before, on my Stuart steam hammer, and on the Quorn grinder castings, and obtained a reasonable finish by brushing final coats . ( I'm not proposing to spray paint, so hence my specific query below ).

 The smoothing of the castings has been done pretty much as Prof. Chaddock has described in his Quorn write-up, time at the sink with flour grade wet and dry used wet, a bit tedious but gets there after various episodes of building up and flatting down a number of applications.
 
 The colour coats are going on fairly smoothly, but I could do with flatting them just a little between coats, until I have enough depth to try leaving a final, unmolested, top coat. I'm using a claret red, which has a certain transparency to it, and will need more than a couple of coats to look solid.
 I could,/ may, go back to the sink with very fine, rather worn-out W+D paper and the same slow business on the colour as I did on the primer coats. But, I was wondering if T-Cut polish/ restorer used on a soft rag, and the job rinsed afterwards,  would achieve the gentle flatting more easily than the awkward scraps of W + D paper, a bit difficult to get into corners...   I happen to have some Perspex polish here -( would need to buy a can of T-Cut ) - is that any use to me for the same mild flattening purpose, or is it best not tried. 
Would welcome comments on this,  thanks, Dave

Offline Jasonb

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Re: T-Cut or not T-Cut? ( that is the question...)
« Reply #1 on: June 10, 2023, 06:55:35 AM »
I think the biggest problem with anything on a cloth is it will tend to follow the imperfections where even soggy wet and dry will ride over the high spots and take them off but not sag down into the low spots.

Usual quality car bodywork practice even after spraying is to flat sand to remove all imperfections and then switch to compounds and mops to bring the shine back up which is really making finer and finer scratches to remove those from the sanding an initial compounds
« Last Edit: June 10, 2023, 06:58:58 AM by Jasonb »

Online Jo

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Re: T-Cut or not T-Cut? ( that is the question...)
« Reply #2 on: June 10, 2023, 07:08:34 AM »
  the awkward scraps of W + D paper, a bit difficult to get into corners...

Try sticking those on some wooden coffee stirrers to make them easier to use  :)

I have a rubbing compound in the workshop which is more of a paste than a liquid polish which could be used on a papered stick.

Jo
Enjoyment is more important than achievement.

Offline petertha

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Re: T-Cut or not T-Cut? ( that is the question...)
« Reply #3 on: June 10, 2023, 07:15:06 AM »
Have you considered very fine abrasive scuff pads? They leave a very pleasing satin matte finish & are very conformable to curved surfaces so it looks even. The finishing folks use this to take the gloss off for inter-coats without removing much of any material, or in cases like yours where they want a uniform satin finish to what was more gloss which otherwise usually requires a flattening agent or specifically formulated clear top coat. I use these pads all the time on aluminum parts for example.

https://www.woodessence.com/Abrasives/Scuff-Pads-Sponges


Offline A7er

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Re: T-Cut or not T-Cut? ( that is the question...)
« Reply #4 on: June 10, 2023, 08:45:39 AM »
It might help with the sanding or polishing if you had a small electric sander. That was my line of thinking when I converted an Oral-B pulsar electric toothbrush to do the job. When I say converted, what I mean is that I hot glued a lolly stick to the back of the toothbrush, no need to cut the bristles off. They may even be useful in polishing the awkward spots. I have used it a lot when sanding my PLA and resin 3D prints, and also sanding the filler to smooth the surface. Various grades of sandpaper can be stuck to the lolly stick with double sided tape.

Safety notice. Do NOT use this on your teeth.

Offline Chipswitheverything

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Re: T-Cut or not T-Cut? ( that is the question...)
« Reply #5 on: June 10, 2023, 09:14:56 AM »
Thanks to all for the comments and helpful ideas.  The castings are the ones for the Stuart Major beam engine, and as per most copies of historic engines they exhibit the most awkward combination of fiddly re-entrant shapes and not very precisely cast moulded decorative features, so are always going to be a bit of a pest to get into to flatten down.  I think Jason is right , that persisting with W + D paper in some form does usefully attend to the slight high spots; and it is at least simple to do , if long-winded.
 I painted the Quorn grinder during the winter, which posed snags of getting some heat into the paint drying , now the summer weather is here, nice, but a bit too warm in the afternoon to keep the brushed paint flowing for brushing out time...! Dave

 

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