Can glass bead damage good valve seats ?

I begin rebuilding a 263 Buick engine , Str8 .
For now I removed the head , checked the valves / seats , clean with coumpound , all is nice . The engine was rebuild before in 1995 , so I mostly check everything , just to be sure of what I have .

The head is really dirty , a lot of carbon inside , and the shape of the T siamese intake makes it hard to reach .

I can glass bead it at home , I have compressor , pressure pot , glass bead , cabinet , etc ..

Is there a risk to ruin the valve seats ?
Thanks a lot .

 

No, bead away, if the seats are in good shape, just lap them in afterwards with grinding compound. if they needed work anyways.... go get a full valvejob.

 

The machine shop will hot tank the heads anyway so save your work for something else.

 

Too late
This engine won t go to the machine shop for now .
It s been rebuild in 1995 and quite not droven .

So I don t take a big chance running it "as his "
Just dismanstel everything , check . Etc .

For the machine shop , I ll need a spare head 248 or 263 to port it , the first one will be quite stock .

Did it . The glass bead had already used , so was really gentle . More dust than sand , and I use a mosquito screen before the blast pot I have to check the seats with coumpound and Prussian blue , but if seems ok .
It s clean
The goal is a 263 in the 1938 on my avatar .
I began last week ..

 

i worked in a machine shop redoing heads.. we glass beaded the heads... they all ran great..

 

Now spend a lot of time cleaning the beads out of every nook and cranny. There is an oil passage in that head that feeds the rockers. Beads will kill rockers and valve guides & stems in no time.

Dan

 

I ve used duct tape to block the oil and water passages , and wood for the valve guides, not so crazy