What am I doing wrong ?

[Bammer]

Having a problem at the moment with flat patches when polishing.

I puting 6 coats of CA and sanding with 400 with the lathe stopped, then as I'm polishing I'm getting these flat patches ..

Usually on darker woods

Any ideas what causes this ?

 

[Bammer]

Sorry about the rubbish photo ...

 

[bellringer]

normally flat patches are were you have sanded though the coats of ca

 

[bassethound]

I have never seen that, maybe it's moisture?..

 

[Phil Dart]

AsAlex has said. That looks to me like over-sanding.

 

[Bill Mooney]

It could be contamination. After sanding clean the timber with meths before applying ca, this might do the trick. I would use a higher grit than 400 for final sanding.

 

[Terry Q]

I think what is happening is dust build up on the sand paper that burnishes the CA.

 

[Jim]

As stated above, may be due to over sanding, but i have seen similar when using CA on oily woods ..

 

[Penpal]

So many possibilities Brad but one suggestion I have looking at your picture is the spacers are flush with the wood I prefer undercut ones and measurement to prevent CA flowing to the spacers. Also facing the blanks and sealing those ends with CA can help a great deal.

Peter.

 

[Grump]

400 grit s far to course for finishing with CA.
Start with 800 maximum and and work through to 12000

https://www.google.co.uk/search?q=m...7.8615j0j8&sourceid=chrome&es_sm=122&ie=UTF-8

 

[rayf6604]

You could also try using Farecla Profile 200 and 500 plastic polishing compound . I use this from 600 grit and I get a mirror finish on CA and acrylic. I use Hut plastic polish after the Profile 500

 

[wm460]

Did you use that accelerator?

 

[silver]

Everyone has a different way of finishing CA, allot of views above are right and you may try one or all of them and not correct what you do.

However, I believe that 400 is far too coarse. I start with 1500, (lathe spinning) then go through from 3600 to 12,000 mm.(lathe stopped and spinning)

As for accelerator, why use it? (If you have of course.) more haste less speed. :wink:

What wood is it? Yes, oil does cause problems. Clean it well but it may come and bite you later. (Been there done that)

 

[Bammer]

No accelerator
This was Black Walnut, also have had it happen on African Blackwood.

I have more to be done so we'll see.

I can see some valid points and will try to adjust accordingly

I may have changed the way i do it over the last few months, that cradle took over my free time for quite a while .

Thank you everyone for your tips ...

Brad

 

[Grump]

If you fancy a trip to Stevenage I would be happy to show you what / how I do my finishing, let you practice here and the kettle is always on.

 

[Bammer]

Just might take you up on that one day, cheers

 

[wm460]

A great offer for you Brad.