<p>I just received a new SLA printer from AliExpress. There are scratches of different shapes on the bed, as seen on the photo. I am particularly worried about a set of scratches of about 0.2&nbsp;mm depth seen at the top right, but there is also a lot of shallower scratches at the bottom right.</p>

<p><a href="https://i.sstatic.net/LfrQ6.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/LfrQ6.jpg" alt="SLA printer, scratched bed"></a></p>

<p>The seller says that it is not a problem and it results from "testing". I am not sure. I have never used SLA printers but I have used an UV resin as a glue and I frequently scratched the glued objects to make the glue adhere much more strongly.</p>

<p>Do these scratches decrease the usability of the bed?</p>

CC BY-SA 4.0
2020-01-17T11:21:54.237Z
Don't you mean to ask "Do these scratches decrease the adhesion of the resin to the bed?", the quality of the plate has already been decreased, you might be after useability instead!
0scar
CC BY-SA 4.0
2020-01-17T12:02:01.910Z
Oscar, I am new to 3d printing. Do the scratches matter? Do they decrease the usability?
scriptfoo
CC BY-SA 4.0
2020-01-17T14:01:07.253Z
I have no SLA experience, but others may answer this question (@Trish ?)
0scar
CC BY-SA 4.0
2020-01-17T14:03:05.747Z
Tell the seller to quit lying and give you a clean bed.   Genuine testing does not degrade the item under test.
Carl Witthoft
CC BY-SA 4.0
2020-01-17T20:38:40.317Z
@0scar my knowledge on SLA is theoretically only, but I would deem a scratch that is more than 1 layer deep as excluding defect.
Trish
CC BY-SA 4.0
2020-01-17T21:37:35.263Z
I also have no experience but I agree with Carl, Trish, and Oscar.  Testing should do no damage.  If it does, the damage indicates a problem, and both the problem and the damage must be repaired.  And, any imperfection on the order of a 1/4 layer or larger is a problem.  In best case, you have little scratch lines stickout of the bottom of every print.  In worst case, you create a bubble of uncured resin that degrades the adhesion, or you create some micro-feature which increase the adhesion so that objects are harder to remove from those spots.  Either way, it isn't good.
cmm
<build-plate><sla>
New 3D resin printer with a scratched bed - will it work well anyway?
scriptfoo
# New 3D resin printer with a scratched bed - will it work well anyway?

(Asked by: username_0 on 2020-01-17)

I just received a new SLA printer from AliExpress. There are scratches of different shapes on the bed, as seen on the photo. I am particularly worried about a set of scratches of about 0.2 mm depth seen at the top right, but there is also a lot of shallower scratches at the bottom right.

[![SLA printer, scratched bed](https://i.sstatic.net/LfrQ6.jpg)](https://i.sstatic.net/LfrQ6.jpg)

The seller says that it is not a problem and it results from "testing". I am not sure. I have never used SLA printers but I have used an UV resin as a glue and I frequently scratched the glued objects to make the glue adhere much more strongly.

Do these scratches decrease the usability of the bed?

**Tags:** build-plate, sla
> **Comments:**
> **username_1**: Don't you mean to ask "Do these scratches decrease the adhesion of the resin to the bed?", the quality of the plate has already been decreased, you might be after useability instead!  
> **username_0**: Oscar, I am new to 3d printing. Do the scratches matter? Do they decrease the usability?  
> **username_1**: I have no SLA experience, but others may answer this question (@Trish ?)  
> **username_2**: Tell the seller to quit lying and give you a clean bed.   Genuine testing does not degrade the item under test.  
> **username_3**: @0scar my knowledge on SLA is theoretically only, but I would deem a scratch that is more than 1 layer deep as excluding defect.  
> **username_4**: I also have no experience but I agree with Carl, Trish, and Oscar.  Testing should do no damage.  If it does, the damage indicates a problem, and both the problem and the damage must be repaired.  And, any imperfection on the order of a 1/4 layer or larger is a problem.  In best case, you have little scratch lines stickout of the bottom of every print.  In worst case, you create a bubble of uncured resin that degrades the adhesion, or you create some micro-feature which increase the adhesion so that objects are harder to remove from those spots.  Either way, it isn't good.  

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## 0 answers

