Woodworking Talk banner

1 - 11 of 11 Posts

·
Registered
Joined
·
293 Posts
Discussion Starter #1
I'm looking at getting a Porter Cable dovetail jig model 4212. It is a used one but seems to be in pretty good condition. When looking it up on the internet it comes with a 7 degree bit, I would not get that. Can I use a 14 degree bit or others, or do I always have to use a 7 degree? Thanks :)

Eric Williams
 

·
Sawdust Creator
Joined
·
8,047 Posts
Anguspapa said:
I'm looking at getting a Porter Cable dovetail jig model 4212. It is a used one but seems to be in pretty good condition. When looking it up on the internet it comes with a 7 degree bit, I would not get that. Can I use a 14 degree bit or others, or do I always have to use a 7 degree? Thanks :)

Eric Williams
I believe you do need the 7 degree one.....but I guess I'm not positive on that. That said....I love mine.
 

·
John
Joined
·
3,028 Posts
I'm looking at getting a Porter Cable dovetail jig model 4212. It is a used one but seems to be in pretty good condition. When looking it up on the internet it comes with a 7 degree bit, I would not get that. Can I use a 14 degree bit or others, or do I always have to use a 7 degree? Thanks :)

Eric Williams
For half blinds I don't think it matters. For through dovetails the fingers on the comb are tapered to match the angle on the bit so for those you will need the 7°:smile:
 

·
Registered
Joined
·
293 Posts
Discussion Starter #4
Well I got my jig but no bits. I really can't argue, it is the PC 4212 model and it only costs $60.00, not $200.00. I have learned that I can use the 14 degree bit, I want that for show purposes. What I'm trying to learn is, do I have to have the dovetail bit and the straight bit when doing full dovetails? The instructions from porter cable say that the dovetail is used on 1 board and the straight bit is used on the other, but when looking at what other people have done it seems that it is dovetail on both pieces. I'll be making valet boxes. I would like to buy and use a 3/8 & 1/2 dovetail, so if I do need the straight bits what size do I need? Thanks once again! :)

Eric Williams
 

·
John
Joined
·
3,028 Posts
Well I got my jig but no bits. I really can't argue, it is the PC 4212 model and it only costs $60.00, not $200.00. I have learned that I can use the 14 degree bit, I want that for show purposes. What I'm trying to learn is, do I have to have the dovetail bit and the straight bit when doing full dovetails? The instructions from porter cable say that the dovetail is used on 1 board and the straight bit is used on the other, but when looking at what other people have done it seems that it is dovetail on both pieces. I'll be making valet boxes. I would like to buy and use a 3/8 & 1/2 dovetail, so if I do need the straight bits what size do I need? Thanks once again! :)

Eric Williams
Hi Eric Check the picture. On through dovetails the pins are cut with the straight bit using the comb with the tapered fingers. The taper on the fingers matches the angle on the dovetail bit. So to answer your question, with a jig, at least the lower end ones, you need to use the bits that the jig was designed for. Not sure about the higher end jigs like the Leigh. I know those have a myriad of adjustments available but don't know what they all are or do.:smile:
 

Attachments

  • Like
Reactions: Anguspapa

·
Registered
Joined
·
293 Posts
Discussion Starter #7
Well after you guys helping me I called PC, they said all I can use is 7 degree. :( Oh well. As far as the size of the dovetail and straight, the dovetail can range from 17/32 to 3/4 then comes the straight, the dovetail and the straight must equal 15/16. So if I'm using a 9/16 dovetail my straight would be 3/8. Just like always, thanks for all your help!

Eric Williams
 

·
Registered
Joined
·
293 Posts
Discussion Starter #8
In the instructions, for half dovetail, my bit guide suppose to be at 3/8 past the template. But what is the Tail / Box Guide suppose to be at? This is the guide that is built on the unit its self, not on the guide. I even called porter cable up and they could not answer the question! They gave me another number to call to talk to the engineers, of course there closed. I'm willing to bet there are people on this chat line that are better at using this unit better then anyone at Porter Cable.

Eric Williams
 

·
John
Joined
·
3,028 Posts
In the instructions, for half dovetail, my bit guide suppose to be at 3/8 past the template. But what is the Tail / Box Guide suppose to be at? This is the guide that is built on the unit its self, not on the guide. I even called porter cable up and they could not answer the question! They gave me another number to call to talk to the engineers, of course there closed. I'm willing to bet there are people on this chat line that are better at using this unit better then anyone at Porter Cable.

Eric Williams
Hi Eric - not sure if I understand your question but here goes. The box joints and through dovetails go all the way through the board. For half blinds, they go all the way through on the tails board and only halfway through the pin board.
 

Attachments

  • Like
Reactions: Anguspapa

·
Registered
Joined
·
293 Posts
Discussion Starter #10 (Edited)
In more basic words, I'm trying to figure out how far down my dovetail bit and straight bit needs to be when doing through dovetails.


image-887752232.jpg

Thanks

Eric Williams
 

·
John
Joined
·
3,028 Posts
I'm more basic words, I'm trying to figure out how far down my dovetail bit and straight bit needs to be when doing through dovetails.


View attachment 77704

Thanks

Eric Williams
Hi Eric, at least equal to the thickness of the boards you are using. Some like to go a bit deeper so the joints are slightly proud on the sides, that way they are sure to sand flush.:smile:
 
  • Like
Reactions: Anguspapa
1 - 11 of 11 Posts
Top