Iroko sanding.

[Richard J]

Hi.

I am working on a large Iroko platter, and have some micro scratches in it that look bad in the sunlight, I have worked up to 600 grit klingspor, but as Iroko seems greasy/oily it clogs up the sand paper very quickly and makes the situation worse.
What am I doing wrong?

 

[CHJ]

Basically you are not removing the scratches from a previous grit.

But a few of questions:
1. how are you sanding, by hand or power?
2 with lathe revolving(what speed) or stationary?
3. are the scratches more visible in a particular area.

Try rotary power sanding with lathe at 500-750 RPM and slow seed hand drill.
Try sanding with the lathe stationary and With the Grain.

You should not need to sand below 240 or 320 grit if you are using a sanding sealer, as long as you can't see the scratches that are aligned with the grain or are very small and rotary so that the eye/brain does not perceive them.

Burnishing a wood such as Iroko to the point that you have a shiny surface can be counter productive in its ability to take and key a surface finish.

 

[Richard J]

Thankyou for your reply,
I have the piece still on the machine. I use a flapper disc on a small angle grinder with a 240 grit, obviously with the lathe running, to get a reasonable finish, and remove any ridges etc, ( I do a lot of welding, so angle gliders are part of my work up!!!) ( feel guilty when not using them!!) then work from 240 down to 600grit wrapped around polystyrene blocks. I couldn't see the scratches, until I took the piece out into the sunshine.
No the scratches do not seem to be in a particular are.
I generally sand at full rpm. Tried slowing it down, but seems better at 2350rpm

R

 

[Richard J]

Oh and please don't frown at my Heath Robinson methods!!! I am learning!!! Slowly but surely.

 

[CHJ]

Keep your metal work methods well away from the wood lathe.
Keep the wood revolutions down if it's a platter then 250 500 rpm max.
Sand with a small strip of sharp abrasive in the hand, if it feels hot to the fingers you are pressing too hard or the abrasive is blunt.
Move the abrasive around, do not keep it positioned in one spot so that it generates circumferencial scratches.
Stop the lathe and check for deep scratches in any cross grain areas, remove any seen, by hand sanding with the grain, move on to next grit and again check for scratches.

If you want to power sand use a slow speed hand drill and vekcro backed abrasive on soft sanding pads.

 

[CHJ]

Caution when using Iroko, some folks are or rapidly become very allergic to it, if face starts itching or signs of histamine reaction or body rash appears leave it alone.

Edit:- See this old thread

 

[Richard J]

Thanks again for your help.
I will try to behave with my welding gear on wood.
Will try slow rpm with new paper
Cheers
R

 

[Claymore]

..........

 

[Dalboy]

Iroko is terrible I had a round of it that was 4" thick and a good 10"-12" diameter and donated it to my club for a raffle prize as it effected me terrible

Keep your metal work methods well away from the wood lathe.
Keep the wood revolutions down if it's a platter then 250 500 rpm max.
Sand with a small strip of sharp abrasive in the hand, if it feels hot to the fingers you are pressing too hard or the abrasive is blunt.
Move the abrasive around, do not keep it positioned in one spot so that it generates circumferencial scratches.
Stop the lathe and check for deep scratches in any cross grain areas, remove any seen, by hand sanding with the grain, move on to next grit and again check for scratches.

If you want to power sand use a slow speed hand drill and vekcro backed abrasive on soft sanding pads.

Just out of interest Chas what are you useing as a power source for the battery drill as i have an old bosch drill that I can use for sanding
Sorry for the diversion

 

[CHJ]

....Just out of interest Chas what are you useing as a power source for the battery drill as i have an old bosch drill that I can use for sanding
..

It's a basic DC power Pack (glorified Battery Charger) I made up about 45+ years ago Derek just a multi tap transformer I wound and some silicone diodes. (complete with home made ammeter, circuit breaker and a current override switch for those short burst of overload that are a must for a home workshop prone to running ex-aircraft series motors.)