Blopturp... What is that?

Today I am going to talk about blopturp.  You may have seen it mentioned in a few of my previous posts and and wondered...

What is blopturp?  Blopturp is an oily mixture of  40% boiled linseed oil, 40% Penetrol and 20% turpentine.  Used, by some, in the restoration and preservation of historic wood windows.

Why would I want to use blopturp? Well, first it penetrates the wood and fills the pores which helps to protect against denting. It helps to condition and consolidate the wood.  It also retards checking, cracking and shrinking, helps to waterproof the wood and leaves a nice finish to which to apply oil based primer and paint.  All good things, when restoring historic wood windows.

How do I use blopturp?  Easy, just brush it on with a paintbrush.  After you have stripped off the old paint or finish and completed the sanding, brush it on your clean dry wood in successive coats until it quits soaking in.  After that wipe of the excess with a dry rag.  That's it!

Where do I get blopturp?  You mix it yourself from boiled linseed oil, Penetrol, and turpentine, all available in various sizes, at the local big box.   Although, for the gallon size of Penetrol I had to go to the paint store.

Let's take a quick look at the ingredients.

Boiled linseed oil (BLO) is made from linseed oil, a natural oil extracted from flax seed, and has been used as a wood finish for hundreds of years.  Back in the day linseed oil, which has a very slow drying time,  was boiled to make it thicker and dry faster.  Today the addition of chemical solvents accomplish same thing as boiling did back then.  BLO is also used as a paint binder for oil based paints and primers.

BLO does have its draw backs.  It yellows with age and some say it causes mildew growth.  I have used straight BLO on wood and wicker in the past and never experienced any mildew or ill effects.

Penetrol is a product made by Flood.   It is a paint/finish conditioner which helps to increase penetration and adhesion of other finishes.  In other words, it helps other finishes sink in and stick better.  Penetrol helps the BLO seep deeper into the wood.

Turpentine is a distilled resin obtained mainly, from live pine trees.  It is a solvent used in the thinning of oil based paints and producing varnishes.  Turpentine has many other industrial uses and in the past was used as a sort of "medicinal" cure all, and can still be found today in Vicks-Vapo-Rub. Turpentine helps to thin the BLO and I'm told helps to alleviate some of the yellowing that can occur from using BLO.


Do I have to use blopturp when I restore my old windows? No, this is the mixture I choose to use. Many window restorers have their own 'concoctions' that they use, some use a 50/50 mix of BLO and turpentine still others use nothing. The National Parks Service, the government entity charged with overseeing our national historic sites, recommends three applications of boiled linseed oil 24 hours apart, in their preservation brief on historic wood windows.  The choice is yours, blopturp, blotine, your own preferred mix or nothing.  Use what you are comfortable with and what fits your time and budget constraints. 

Before I end this post I feel I must mention a few words about safety.  These are dangerous chemicals and must be treated as such!  Read all safety precautions on the containers.  Become familiar with the first aid treatment for exposure.  Always store your mixed chemicals in clearly marked, appropriate containers.  Be aware of any flammable and combustible warnings and dispose of used items accordingly.  Finally, keep all chemicals out of the reach of children!

Remember SAFETY FIRST!

Well, that is it for today.  Please contact us if  you have any questions.

Holli